Chapter 20 Chapter 12 Developmental Psychologist-2

"Ants know how to accumulate food, but lazy men prepare for it." The behavior of ants that Solomon (or whoever wrote it) wants us to emulate involves accumulating and hoarding in good time.However, the social cooperation of ants is more important.They have been fully socialized since emerging from the larval state, and their tiny nervous systems are programmed to automatically respond to the chemical cues and touch of their peers with appropriate social behaviors, such as gathering food, clearing dens, Fights defensively, feeds larvae and mother ants.In contrast, we humans take 15-20 years to become relatively social, and even then our behavior is not fixed but must be constantly adjusted to our roles throughout our lives. change.

For more than half a century, developmental psychologists have used a variety of methods to gather evidence about human social development.With notebooks on their laps and stopwatches in hand, they observe toddlers at home or in kindergarten, preschoolers or elementary school children in playgrounds and classrooms.They interviewed parents and harassed the parents with questionnaires.Record and analyze a large number of children's conversations.They tell the children the beginning of the story and let them make it up.They designed hundreds of experimental situations to measure levels of social development at different stages.They calculated correlations between hormone levels in the blood and sex-type behavior.

From all these activities (and many more), they made a great deal of discovery.Some findings support developmental psychoanalysis, others support a social learning perspective, still others support cognitive-developmental theories, and many more find support for all three.We don't need to categorize them, but just glance at some of the more interesting discoveries. Take turns: The earliest lessons in social behavior are learned at home, where, in addition to learning to trust another human being, babies learn a crucial lesson in social relationships at home, namely, taking turns when communicating.The parent talks to the baby, waits for the baby to respond with a voice or a smile, and then continues.Babies sense this pattern and know to take the same turn-taking pattern when interacting with another baby of the same size long before they learn to walk or say a word.In the following conversation, recorded from a 1975 study, 13-month-old Bernie watches 15-month-old Larry talk to a toy.Finally it was time for him to "speak":

Bernie: Da...da. Larry: (continues watching, laughing) Bernie: Da. Larry: (the laughter gets stronger) The same sequence was repeated 5 times.Then Larry turned away and gave a toy to an adult.Burry followed him. Bernie: (waving both hands and staring straight at Larry) Dah! Larry: (looks back at Bernie and laughs again) After nine repetitions of this, Bernie gave up and wobbled away. Play: Developmental psychologists L. Alan Sloof and Robert G. Cooper call play a "bought laboratory," where children learn new skills and practice old ones.Babies don't play together because it requires emotional and cognitive skills that take two to three years to develop.Put two toddlers together, and they'll usually just look at each other, watching each play by itself, or next to each other and playing with each other.However, by age 3 or thereabouts, they start playing together (not necessarily the same game), and by age 5 they are playing together in a cooperative manner.

In play, toddlers and preschoolers learn their first lessons in self-control.They found that if they are too domineering, the adults who are watching can't tolerate it, and it may cause the other party to retaliate or be unwilling to play with them.They learned to share, even though it took a lot of effort to recognize it.They gradually develop a preference for playing with other playmates, and by the age of 4, this habit has transformed into friendship, which can be seen in the relationship and sense of responsibility for each other. By age 3-4, they begin to learn the rules of play and learn the basics of right and wrong from playing with older children: "Try three times and you're out", lose your temper and lose your temper. Will give you more opportunities, but may expel you.

Around the same time, they began lying and covering facial expressions that might reveal their intentions or speaking in a more mature tone.One research team suggests that this behavior is often the result of direct parenting. (“Remember, even though what you’ve got in mind is a toy, thank grandma for buying you the top.”) Take on roles: Sloof and Cooper also call play "social workshops," where children try out the rules, alone or with other children.They often play Mummy and Daddy, Mummy and Baby, Daddy and Baby, Doctor and Patient, and Wreck and Rescuer.They especially like to play parent games, and make their own parents act like little kids, telling them to eat this or that, or go to wash their ears and wash their hands, or go to bed.Whether one interprets the game in a psychoanalytic, behaviorist or epistemological way, it still serves as training for social life.A recent study even found that the more socially imaginative games preschoolers play, the more "socially competent" the children are, as rated by teachers.

Sociability: Elements of sociability are readiness to play with peers, permission to give in, and being liked or accepted by other playmates.The way developmental psychologists measure popularity is sociometrics.They asked the children in a particular playgroup which of the children in the group they "liked very much" and which ones they "didn't like very much."Subtracting the negative answers from the positive answers and adding up the points simply gives each child how popular they are with the organization. Self and group: In playgroups, especially in the classroom, close contact with other children stimulates the development of a sense of psychological self (which is different from the physical sense of self that a toddler feels in a mirror) .By age 8, children begin to realize that they are different from other children, both internally and externally, and that, in fact, they are all unique.

At the same time, they began to pay great attention to the rules of the group, such as the rules of the game (which side to choose, take turns, and when it was the turn to hit the ball, toss a coin to determine the first side) and loyalty to the group. ("Reporting" on peers to parents or teachers is a condition of exclusion).Even at elementary school, it is extremely important for a child to wear whatever clothes are in fashion in the class.As they approach adolescence, the need to obey peers, group routines, tastes in clothing, ways of speaking and smoking, music, slang, drug use, sexual behavior, etc. are all extremely strong.The norms and values ​​of teenage peers and groups vary widely across ethnic groups and social and economic levels, yet the need to obey is ubiquitous.After the early teenage years, it will slowly disappear throughout the teenage years.

Gender-Type Behavior: Fifty years ago, many people believed that throughout childhood, and especially as they approached adolescence, children adopted gender-appropriate behavior.In the '60s, with the advent of the feminist movement, many believed that many gender-type behaviors turned out to be socially taught, not genetic, and would soon disappear.It is true that most of the similar behaviors also disappeared, but some of them remained, and, as we have seen, they will continue. This may be partly due to biology.In the 1970s, radioimmunological studies showed that hormone levels rise at about age 7—well before secondary sex characteristics emerge and sex-type behavior is exaggerated.For a reason, from the age of 7, few girls play vigorous games like boys, and they don't get dirty like boys, and few boys before teenage years. Children pay as much attention to clothing and hairstyles as girls do.

In many cases, however, the accumulation of gender-typed behavior in pre-adolescence and adolescence appears to be learned from a social perception of a place one is likely to occupy in society as an adult. A 1990 national survey of 3,000 boys and girls in grades three through ten, conducted for the American Association of University Women, found that girls had only slightly less self-esteem than boys in elementary school ; in middle school, boys' self-esteem declined slightly, while girls' self-esteem declined sharply; this asymmetry persisted through high school.The disappearance of self-esteem affects girls' social behavior in many ways, hinders many actions and abilities, and causes them to pay extreme attention to appearance.Girls are less likely to "feel good in many ways" than boys are generally confident, comfortable speaking up in class, and willing to talk to others when they think they are right. The teacher argues.

Empathy and altruism: In the 1960s, some psychologists became interested in "prosocial behavior"—the cooperative way of all those behaviors that make social life possible.Many are social psychologists, but others are developmental psychologists who are drawn to one form of prosocial behavior, altruism.Much prosocial behavior is motivated by selfish ends—we stop at red lights, we pay our taxes not out of love for our fellow man, but out of self-interest—but altruism is Motivated by concern for one other person.A question of interest to developmental psychologists is how such behavior arises, since it often contradicts the strongest of all motives, self-interest. Over the past 30 years, hundreds of developmental psychologists have conducted more than 1,200 altruism studies, using many of the empirical methods mentioned earlier.The answer to the question "How is the idea of ​​altruism formed?" seems to be that it arises from a confluence of influences: the natural tendency of humans to feel sad when they see another human being in pain, cultural values, the child’s ability to imagine how another person feels, social experience (helping others makes the helper think of himself as a good person and is seen by others as a good person) and real-world knowledge Judgment based on the fact that he knows the consequences of helping or not helping a person in pain.A few notable examples: —At 10 months or a year, as stated above, a child who sees his mother in pain whimpers, or crawls away crying, while at 14 months he may pat Pat her, hug her, or kiss her. ——After 18 months, the child will try to comfort another crying child, or ask an adult to help. ——By the age of 2-4, a child will ask another child who is injured or in pain about pain, will find ways to comfort or ask for help, and will also find ways to prevent other children from being hurt ( For example, such as warning them about the danger, etc.). -By age 7, most children will help a strange child who appears injured or in some difficulty. ——From the age of 7, children will be more and more willing to give their money or toys to a poor child, or to help a child in difficulty, even if it means that the child has to give up something he wants to do matter. Developmental psychologists see a pattern in the data.There appears to be a series of distinct stages in the development of altruistic behavior, but there is no agreement on how many there are or what they are.There is a notion of four stages, another of five, and a six-stage model that has just been developed by longtime altruism expert Dennis Fletcher of Simon Fritz University in Burnaby. Proposed by L. Krebs and his colleague Frank van Hesteren.The six-stage theory of Krebs and van Hesteren is based on (1) obedience to authority, requiring personal security and security, (2) maximization of personal growth and compensation decisions , (3) identify with roles and collective expectations, as well as reciprocity and cooperation, (4) sense of social responsibility and act in accordance with internalized values, (5) respect the rights of others and be willing to sacrifice for the benefit of others, (6) respect The moral values ​​of all, agree with all human beings.Moral Development: Altruism is only a consequence of the development of a moral sense.Interest in some aspects of mental development began in 1908, when the eminent British psychologist William MacDougall formulated a set of moral developmental principles based on his knowledge of human psychology in general. theory.In the 1920s, Piaget began experimental investigations to understand children by observing them playing games and telling them stories about making small mistakes, and then asking them what kind of appropriate punishment they would give them. (An example: In the first case, a boy inks his father's ink tank in order to appear helpful, but accidentally gets the ink on the tablecloth. In the second case, a A boy plays with his father's ink cartridge and spills ink on the tablecloth. Should the boy be punished the same in both cases?) Piaget concluded that moral behavior, in the context of play, develops in three stages between the ages of 4-12 years, starting with no imposition of rules imposed by parents or older children. Unquestioned acceptance, and finally the realization that the rules are made by people and can be changed by mutual consent.Likewise, the basis on which an action (such as splashing ink) is judged to be right or wrong can vary between the damage the action caused and the person's intentions. Piaget's Moral Judgments of the Child was published in England in 1932. This book triggered a lot of research on moral development in the United States, but most of it was just patchwork and nitpicking.The next big leap, a milestone in the study of moral development theory, came 30 years later, with the work of Lawrence Kohlberg.He invented a new way of measuring moral development, revised it over a 25-year period, collected and analyzed data, and proposed a six-stage theory of moral development.This theory has since become a classic and model in this field, and others have either followed or opposed this theory. Kohlberg would have made a very good pastor if he hadn't felt that his favorite job was being a moral developmental psychologist.He is serious and considerate, warm and gentle, humorous, talkative and fanatical, and cares deeply about racial issues and other moral life.He is indifferent to the outside world, the archetype of the intellectual professor, he is baggy and rumpled, his hair is disheveled, his suitcase is badly worn and overfilled, his glasses are pushed up and rested on his forehead, and then forgotten, Always stay on the forehead. The scion of a businessman, he was born in 1927 in Bronxville, a wealthy New York suburb.He attended Philippe High School in Andoire, graduating at the end of World War II.Instead of going on to university, he was driven by conscience to become a sailor on a merchant ship so he could join the cause of smuggling boatloads of European Jewish refugees from the British blockade to Palestine.The experience gave Kohlberg a lifelong interest in the question of when it is morally justified for a person to disobey the law and statutory authority.The experience also brought him lifelong illness: he was caught and held for a while in a military camp in Cyprus, and escaped, but not a parasitic stomach infection Since then, this problem has bothered him from time to time, and he has not healed all his life. Kohlberg earned his undergraduate and graduate degrees at the University of Chicago, where psychology and philosophy (especially ethics) were his two favorite subjects.He had read and liked Piaget's Moral Judgments of the Child, but he felt, in the spirit of American psychology, that a solid theory of moral development should be based on objective methods rather than Piaget's natural Based on observed data.Therefore, for his doctoral dissertation, he created a grading system (which he later turned into a test), which he himself revised and used throughout his life, and from which he formed a recognition of the stages of moral development. Knowledge-development theory.The test consisted of nine moral dilemmas, which researchers posed to subjects one at a time.Each question is followed by a conversation, which is a series of related questions. Here's an example (the "Heinz Dilemma"): In a small European town, a woman is near death from a particular form of cancer; a pharmacist in the town has discovered a new drug that has the potential to save her life, However, he is a profiteer, and he charges 10 times the cost of making the drug.The woman's husband, Heinz, could only borrow half of the money, so he had to ask the pharmacist to reduce the price, but the pharmacist refused.In order to save his wife's life, Heinz considered breaking into the house and stealing the medicine.Should he?Why should it, why shouldn't it?Was it his duty or obligation to steal the drug?If he doesn't love his wife, will he steal medicine for his wife?What if the dying person is a stranger?Will Heinz steal the drug for this stranger?Stealing is illegal; is it also immoral to do so?There are a total of 21 questions in this category. Kohlberg's original example consisted of a representative sample of 72 10-, 13-, and 16-year-old boys in the Chicago area.He tested every 2-5 years for 30 years.After some initial testing, the differences in the answers given by the three age groups led Kohlberg to suggest that moral sense develops at distinctly different stages.Later, when his subjects were older, he found that they progressed through these stages exactly as he had predicted.Here, we present this staged theory in its most recent form, along with typical responses to each stage, both for and against Heinz's drug stealing.This is a simplified form, with some of Kohlberg's original troublesome words altered a bit: - Stage 1: naive moral realism; actions are rule-based, motivated by avoidance of punishment. Supporters: If the wife dies, you're in trouble. Opponents: You shouldn't steal the drug because you'll be caught and sent to jail. - Second stage: pragmatic ethics; actions are based on the desire to maximize rewards or benefits while minimizing negative consequences for oneself. Proponents: If you get caught, you can give him the medicine back and there won't be a long sentence.Jail for a while is not a big deal if your wife is still there when you come home from prison Cons: If you steal the drug, your wife will die before you get out of the cell, so it won't do you much good. - The third stage; socially shared views; actions based on others' expected agreement or disapproval and actual or imagined guilt. Supporters: No one will think you are a bad person if you steal the drug.However, if you let your wife die, you will no longer be able to hold your head up in front of others. Naysayers: Everyone will think you are a criminal.After stealing the drug, you can no longer hold your head up in front of others. - Fourth stage: social system morality; actions are based on whether there will be formal humiliation (not just disapproval) and guilt for causing harm to others. Supporter: No one with a little sense of honor would let his wife die like this.If you don't do this to your wife, you will always feel guilty that you caused her to die. Opponents: You've run out of options, so it doesn't occur to you that you're doing something wrong when you steal the drug.However, when you get to the prison, you will wake up.You will feel guilty for your dishonesty and breaking the law. —The fifth stage: human rights and social welfare ethics; its viewpoint is that of a rational, moral person who believes that values ​​and rights should exist in a moral society; they act to maintain based on respect for the public and a sense of self-respect. Supporters: If you don't steal the drug, you will lose the respect of others.If you allow your wife to die, it may be out of fear rather than reason.You will lose your self-esteem and possibly the respect of others. Opponents: You will lose your standing and respect in public and break the law.If you let your emotions manipulate you and forget about the long-term perspective, you will lose your self-esteem. ——The sixth stage: universal moral principles; the point of view is that all human beings should adopt this moral view towards each other and towards themselves; actions are determined by fairness, justice and consideration of whether one can maintain one's own moral principles. Support: If you let your wife die without stealing the drug, you will always blame yourself afterwards.You will not be blamed, and you will act according to the law, but not according to the standards of your own conscience. Naysayers: If you steal the drug, you will not be blamed by others but you will only blame yourself for not acting according to your own standard of conscience and honesty. Kohlberg had many ardent followers and admirers, especially in the 1960s and 1970s, when his emphasis on justice and approval of the Stage Six decision made the law laughable and thus made him a civil rights A favorite of activists, anti-Vietnam War protesters, and women's liberation activists.However, his tests and theories have been attacked by many developmental psychologists in several places.Some say there is evidence that development is not always upward and orderly (some people jump up at different stages of development, others fall.) Others say that moral thinking is not necessarily Behaving ethically, some people are higher on Kohlberg's scale than their behavior would suggest. (Koleberg insists that most studies show a correlation between stages of moral judgment and actual behavior.) One of Kohlberg's Harvard aides, Carol Gilligan, objected That said, his scale is male-biased: women are likely to respond to moral dilemmas by expressing caring and personal relationships, while men are likely to express them through abstract concepts like justice and fairness.Thus, women are likely to score lower on Kohlberg's scale, just as they are less morally developed than men. Kohlberg bore all these criticisms and attacks without complaint, some with which he himself agreed (and with some revisions) and others which he quietly refuted with new data and reasons .He also gave up two dreams that he spent a lot of time and energy trying to realize.One is a demonstration project to raise the prisoner's moral thinking to the fourth stage through the discussion of the dilemma, and the other is an attempt to use the same method to rescue troubled teenagers. (The results were encouraging, but word of the project never spread, except in a few schools in Cambridge and New York.) These unhappiness and disappointments were added to the constant relapses of his chronic parasitic enteritis, the severe effects of which caused him constant stomach and intestinal pains.As he approached 60, Kohlberg was deeply depressed.He once had a conversation with a close friend about the moral dilemma of suicide.He told the friend that if a person has great responsibilities to other people, that person should stick to them.However, the battle with the disease was too painful. His car was found parked in a tidal wetland in Boston Harbor on January 17, 1987, and his body washed up near Logan Airport three months later.In a loving tribute to the Harvard Gazette of December 15, 1989, three prominent psychologists (Carol Gilligan was one) summed up his contributions: "[ Larry] established moral development as a central issue in developmental psychology almost entirely on his own.” Kohlberg's revisionists didn't disagree with his general theory, they just wanted to tweak it to fit their own experimental evidence.Dennis Krebs of Simon Fraser University is one such person.Krebs, despite his admiration for Kohlberg, with whom he became acquainted at Harvard, has recently published a study showing that when considering Kohlberg's dilemma, no matter what moral level people are In general, people are always at a lower level when dealing with certain things in their own lives. What makes this research noteworthy is that, unlike most other studies of moral development, it was based not on a single test but on real-life situations.Kathy Denton, another author of the study, visited bars, nightclubs, and parties to conduct surveys. She asked some drinkers to participate in a study of "The Effects of Drinking on Judgment."Volunteer subjects (she got a total of 40 people) were interviewed and answered Kohlberg's dilemma questions about the ethics of driving while drunk (Should you keep driving while drunk? If you're drunk but What should I do if I don’t feel drunk? Are you going to be extra careful?), and then perform an in vivo alcohol level test.In a follow-up session at the university, the same group was interviewed again, asked to answer two more Kohlberg dilemmas, and asked how they got home after the first meeting. Denton and Krebs found that people scored higher on tests of moral development administered at the university than when they were drunk; The lower the score.When they are sober, they think it is morally wrong to drive drunk and say they would not do it themselves, but when they drink they tend to adopt less stringent moral standards.Indeed, with the exception of one, none of them drove home after their first meeting, no matter how drunk they were. This is just one example of Krebs' efforts to measure moral development in real life.Over the past few years, he and his colleagues have conducted eleven studies in which they assessed people's moral judgment using everyday dilemmas rather than Kohlberg's. (Two examples: a business dilemma—whether or not to release information that might hurt the sale of the business; a prosocial dilemma—a student has an appointment and is due in minutes It was time, and he was going to be a subject of a psychological study. At this time, he met another student who had problems with taking medicine and needed his help.) In several studies, the volunteers still Talked about some of the dilemmas they encountered in their own lives. For more than 20 years, Krebs has been conducting the study of moral reasoning and behavior, particularly altruism.Why would one devote so much time and energy to a field of psychology that is so controversial and not as practically rewarding as psychometric testing, consumer psychology, and industrial psychology?The motivations of developmental psychologists who concentrate on moral development are varied.Some were realistic students of the 1960s who have since become inseparable from prosocial behavior; others were interested in morality from a religious point of view but felt that the psychological approach was more realistic and some results; and there are dedicated developmental psychologists who are Holocaust survivors, for whom the study of the humane side of human nature is imperative and therapeutic . And then there's someone like Dennis Krebs, whose reasons are extremely specific.He was born in Vancouver in 1942, the son of a carpenter who also invented a device that enhanced the special acoustics of electric guitars.Krebs was a top student in high school, the president of the student body, and despite his lanky build, was an award-winning amateur boxer.When he was 14, the family moved to the San Francisco area, where his father's electronic music business was much bigger.The move had disastrous effects on young Dennis.Here he quickly turned from a highly motivated young man into a juvenile delinquent.As he himself said: I came from a place where I was a role model teenager to live in a culture that I didn't understand, where I didn't fit in, where people made fun of everything about me—my clothes, my accent, my behavior.After meeting a good boxer, I quickly got involved in non-stop fights and gained a lot of fame for it - which in turn led to more fights, although most of the time I Both fought and won, but it also made me part of the gang. He started skipping school, getting into fights, and stealing from stores.Eventually, he got caught and spent months in a juvenile correctional facility as a juvenile delinquent for the first time, then a second time.He got out on bail and really didn't cause trouble for a while.However, one night, because he slept too little and drank some alcohol, he drove very fast and was stopped by the police while staggering.They let him go, but when he left he said some bad words and walked away cursing.He ignored the police flashing their lights and honking their sirens and chased after him, eventually crashing into a utility pole.He was not injured but was taken to the county jail.Inspired by a fit of furious defiance, he unlocked the window and slipped away on a rope made of sheets, all the way to Oregon.He disappeared into the logging camp here, worked desperately here, contemplated life intensively, and then had a plan: I'm past my teenage years and I need a different way of life.I decided to go back to Vancouver and study at the University of British Columbia.At first I spent half a year in a logging camp and saved enough to go to school.Then, I went to college.At this time, I was already in my 20s, several years older than other students, and I felt very backward.Therefore, I studied extremely seriously and became a hard-working student, taking a lot of courses and doing some after-school jobs. I graduated in 1967 at the age of 25, top student with honors in psychology.I applied to Harvard to get a Ph.D., but when I was accepted, it occurred to me that I had been living in fear that someone might expose me because I was a fugitive.Therefore, I decided to turn myself in.I went back to the San Francisco area and turned myself in - considering I was a college student, there was a commotion in the local area, I made headlines in the papers, and I was featured on TV shows —and I was forgiven. Krebs went to Harvard, where he spent a year earning his master's degree and two years earning his Ph. While studying, he has been working odd jobs at Harvard University as the lead assistant for introductory courses in psychology and social relations.He received his Ph.D. in 1970 and was immediately hired by Harvard as an associate professor and head of undergraduate teaching, where he stayed for four years.He then moved on to Simon Fraser University, where he has been a full professor since 1982.At the age of 50, he was still poor, with long hair and a baby face. No one would have thought that such a diligent scholar like him would have such a legendary life. Krebs' resume includes a string of publications, most of them on moral development and altruism.He said dryly: "It is perhaps no accident that I am so deeply interested in moral questions, especially in the question of the development from one moral level to another." During the 1920s, Piaget's early publications launched modern research on cognitive development in Europe and the United States.In America, however, this interest soon waned; behaviorism reached its peak at once, and its successors showed no interest in what they regarded as a new wine in the old bottle of idealism.可是，在60年代，当认知主义开始受到欢迎时，皮亚杰被重新发现了，以他的方式进行的智力发育研究又成了热门。 然而，皮亚杰理论精简的大纲很快就模糊不清了，因为大批的博士竞选人和心理学家进行的成百次皮亚杰式研究所产生的成果修改了原来的理论，甚至向原来的理论提出了挑战。在过去30年的时间内，认知发展这个领域尽管还受到皮亚杰的影响，但它现在已经是一座生长过盛的花园，需要某个人以全新的综合性视点进行大刀阔斧的重新组织。 然而，在这块没有清除杂草的花园里，有无数美好的东西在生长：一些发现给人以启迪，使人愉悦，有时候还会使观赏者大吃一惊。在这里，我们不追求完整无缺，甚至也不想如何具有代表性，而只是随手采摘几把30年的研究花朵和果实。 记忆力：一个不能说话的婴儿，如果是刚刚出生的话，甚至连通过表情或者手势来表达认知都不可能，那么，人们是怎么调查他的记忆力的呢？研究者们已经想了很多聪明的办法来解决这个问题。在1959年进行的一项实验中，对不到一个月大的婴儿进行训练，使其在听到某种特定的声音时转动自己的头（他们在碰触面部时转头，然后得到奶瓶的奖励），一天之后，他们在听到响声时仍然转过头来。这种方法在不同年龄的婴儿身上试过，得出了有关记忆力成长的数据。 在几个月大的婴儿中，用得最多的方法是通过前述的范茨法观察它们的眼部运动。由于婴儿看新事物时比看旧事物的时间长些，这种方法可以得出婴儿对所看到过的东西的记忆的直接指示。 另一个方法是在1979年进行的一项实验里用到过的，这种方法需要一种活动的东西吊在婴儿床上；受试者从2一4个月不等。当婴儿踢腿时，研究者就让活动的东西自己动起来，婴儿很快学会踢东西，以便让活动的东西动起来。接着，他有一个星期的时间看不到这个东西，可当他看见时，他立即开始踢腿了。然而，如果两个星期过去了，他却不踢了。这一次，记忆力的成长又一次得到了准确测量。 这样的记忆力（认知）与更为积极地利用起来的记忆力不太一样，后者涉及婴儿寻找一个被遮盖起来的物体。如果8个月或者9个月大的婴儿两次从两种类似的覆盖物下找回一种玩具，而且如果研究者然后把它放在另外一个覆盖物下面——在婴儿看着的时候——除非允许他在几秒钟的时间内寻找玩具，否则，婴儿会在他原来找到玩具的地方去翻找。他的记忆力在一个原始的水平上发挥作用。可是，几个月后，他不再犯同样的错误了。这种进步是因为某些大脑线路的成熟所致。大脑前皮层的某个特定区域被损坏的猴子总是学不会在正确的覆盖物下找东西。 到5岁时，儿童毫不费力就可以记住好几千单词，可是，他们在听过一些慢慢地读出来的词后，能够记住的最长的数字也只有四位数这么长。到6岁或者7岁的时候，他们可以记住五位数字，到9-12岁时可以记忆住六位数字。可是，这种能力的增加来自成熟的部分没有来自如何记忆数字的知识这部分多。到上学之前，孩子们还不会“排演”（重复或者复习）信息，也不会使用相关的技巧。一年级小孩子的父母经常会感到奇怪，他们的孩子记不住当天在学校里发生的事情。可是，在学校里，孩子们慢慢地学会了记忆技巧，很快就知道了比如说如何想象自己在学校开始的时候自己在班上的情形，因而就能回忆什么事情在先，什么事情接在后面，哪些是再后来发生的。 自我感、能力感：小孩子对自己的世界的探索，是衡量他不断灵敏的自我感和不断成熟的能力感的尺度。在9个月大的时候，孩子们还会用嘴咬物件，或者把东西砸得砰砰响，或者毫无目的地一次又一次地转动物件，可是，到第一年的末尾时，他们开始探索这些物体的实际用途：他们试着从一个玩具杯里喝水，对着玩具电话“说话”等等。他们对探索新地界产生了兴趣，有时候也喜欢爬到母亲看不见的地方。他们见到旋钮就拧，抓到转盘就拨；他们打开衣柜和壁柜，把所有的东西都抱出来。这些活动显示了许多发展心理学家们叫做“能力保持”的东西。探索行为与行为主义的理论相反，它不是受奖励行为的后果，而是自发和自我启动的；人类婴儿和孩子有一种调查其自身对物件发生作用、干涉事件的发展和扩大视野的能力的需要。 另一项能力感成长的显示是，接近两岁的孩子在成功地建起了一座塔，把最后一片积木插到了正确的位置，或者给玩具娃娃穿好了最后一件衣服时会微笑，哪怕没有人在场他们也微笑。同时，孩子开始意识到自我的失败及其意义。杰罗姆·凯根及其同事注意到，在15个月和24个月大的孩子中，如果成人展示了某种高级的游戏，然后告诉他们该他们玩的时候会显示出一种焦虑。这种游戏可能是让玩具娃娃在锅里做菜，然后让两个娃娃吃饭，或者让三只动物散步，然后藏在一块布下躲雨。面对这样一种遵守相对较复杂的游戏规则的挑战，孩子会感到一阵烦燥，会哭，或者抱在母亲身上。凯根解释说，这是一个证据，证明孩子对不能记忆或者不能当着成人的面完成游戏的害怕，因为如果没有旁观者在身旁的话，孩子经常会尝试有法可依的游戏，或者完成其游戏的一部分。 语言及思维：皮亚杰相信，语言在思维的发展过程中只起有限的作用，逻辑思维基本上是非语言的，而且是从行动中派生出来的。首先，对身边的世界做一些事情，然后，再在自己的心里完成这些东西的图象。苏联和美国的发展心理学家们找到了相反的证据。尽管有些思维是非语言的这一点是正确的，可是，语言是一套符号，可以让孩子们得到超凡的自由来通过心理控制这个世界，并按相应的方式对新的刺激产生行为，而不需要直接地体验（很烫，别碰）。著名的发展心理学家杰罗姆·布鲁纳长期以来一直认为，语言是孩子的符号系统中最为关键的一部分，“不仅仅对代表经验而言，而且对转变经验而言也是一种方法”。 这里有一个研究证据，可以证明语言在思维中所起的作用：给幼儿园预备班的孩子们看三个黑色的方框，然后让他们选择一个，如果他们选择了最大的那一个，就对他们进行奖励。等他们学会了选择最大的一个时，再让他们看新的方框，最小的一个跟前面的三个方框中最大的一个一般大。然后，这一次又是选择了最大的方框就得奖励。可是，孩子们没有心理符号来告诉他们“总是选择最大的”，而是不断地选择前面得到了奖励的那一块，尽管这次根本就得不了奖。可是，幼儿园和更大一些的孩子们却很快就能够告诉自己选择“最大的一个”，不管实际的尺寸是多大。 如果单词用来指导思想，则更复杂和更高级一些的问题也能解决。告诉一组9-10岁的孩子说，一边解决很复杂的问题，一边可以说话，另一组的孩子没有得到这样的指令。这些复杂的难题涉及到以最少的步骤把一些圆片从一个圈子里移到另一些圈里去。边做边念的那一组孩子更快更有效地解决了问题，而没有得到指令的那一组就慢些。有意地使用单词使他们找到试一种或另一种方法的新理由，因而有助于他们找到正确的答案。 语言获取：发展心理学家和心理语言学家们（对语言获取和利用感兴趣的一些心理学家）在最近几十年里花了很多时间听孩子们讲话，他们揣摸着他们学习新词的速度有多快，寻找他们所犯的错误和纠正类型，等等。其中的一项发现是，孩子们是以相对一致的顺序发展或者获取新形式的（词尾、动词形式、介词）。在2-4岁的时候，他们的词汇量从几百个增加到平均2600个。（他们每月获取50多个新词。）他们先模仿听到的动词形式，然后对动词词根进行总结，合理地（但是错误地）假设，语言在所有的地方都是符合规则和一致的（“我了吃一块饼干，”“我了看见一只小鸟”），只是后来慢慢地学会使用不规则动词形式。他们很顽固地倾向于这些语法错误，如在下述这段由一位心理语言学家记录的对话中一样： 孩子：没有人不喜欢我。 母亲：不，应该说：“没有人喜欢我。” 孩子：没有人不喜欢我。 （这样的交换重复了8次。） 母亲：不，现在仔细听我说；应该说：“没有人喜欢我。” 孩子：哦！没有人不是喜欢我。 他们在准备好了的时候会自己纠正自己的错误。很明显，他们获取了很多自己并不使用的语法元素，直到某个时候，他们在心里把自己说的话与某种存储的知识进行比较，然后看出两者之间的差别。 吉米：（快7岁）：我想到了您可能喜欢了的一件事情。 母亲：你说什么？ 吉米：我想到了您可能喜欢的一件事情。 有关语言获取的研究中最重大的一项进步是孩子理解句法的方法，句法是词汇在一个句子里的排列顺序，这种顺序表明词汇彼此之间的关系，因而决定一个句子的意义。1957年，B·F·斯金纳出版了一本书，名叫《言语行为》，他在书中完全以操作条件的方式解释了孩子的语言获取情况：当孩子正确地使用到了一个词或者句子时，父母或其他人会表示赞许，这种奖励会激励孩子下次也正确地使用它。 可是，同一年，一位极聪明的年轻心理语言学家诺姆·乔姆斯基在他的《句法结构》一书中提出了极为不同的分析。他强调说，“一定有一些基本的过程在起作用，这些过程相当独立地来自于从环境中得到的'反馈”'，大脑一定具有某种天生的能力，可以使语言产生意义。作为证据，他提出，孩子们会造出无数他们从未听到过的句子，这使通过条件制约进行模仿的说法看上去是对句法形成相当不足的一种解释。再说，孩子努力造出的一些句子虽然经常不合语法，但从来就没有严重违反语法规则。（他们从来就不造反向的句子。）最为重要的是，就算句子的意思是模糊的，孩子们总能够理解真正的意思；他们一定具有某种天生的能力来感受句子的“深层结构”不管“表层结构”到底是什么样子的。乔姆斯基举的一个例子： 约翰容易逗乐。（John is easy to please.） 约翰急于逗乐。（John is eager to please.） 这两个句子的表层结构是一样的，可是，如果你想以同样的形式拆解这个句子，只有一种才有意义： It is easy to please John.（容易逗乐约翰。） It is eager to please John.（急于逗乐约翰） 没有哪个孩子会犯这样的错误；每个孩子都能理解深层结构。第一句里面的“约翰”是“逗乐”的“深层次宾语”，因此，拆解的句子说得通。可是，第二句中的“约翰”是“逗乐”的“深层次主语，”因此，任何拆解只能采取“约翰急于逗乐（某人）”的形式。对深层次结构的理解不是从表层结构或者单凭经验的方法得来的，感受深层次结构的能力是天生的。（可是，乔姆斯基本人或者任何心理语言学家都不曾说过语言本身也是天生的，而只是说，孩子具有一种天生的资质，可以辨认并解释句子的深层次结构。） 有趣的是，乔姆斯基是通过研究语言本身和婴儿行为，而不是通过进行实验得出这个结论的。不过，有一次，心理学家乔治·米勒和其他好几位参与者在乔姆斯基主持的一次座谈会上的确劝说他做一次实验。乔姆斯基曾说过，当一个句子有可能具有两个意思时，讲话的人不能通过音调来搞清楚哪一个是正确的意思；两个句子的深层意思是一样的，而正确的意思是通过上下文来说明的。他举了一个例子。“Flying planes can bedangerous．（开飞机可能是危险的。）／（飞行中的飞机可能是危险的。）”一位与会者向他发难，要他证明他的说法。乔姆斯基写了两段话，在其中一段里，一些住在机场附近的居民抱怨说，他们生活在恐惧中，因为飞行的飞机是很危险的；在另外一段中，居民催促市长说，不要自己开飞机，因为开飞机是很危险的。10位自愿者录了两段的音。乔姆斯的妻子卡罗尔把所有出现这句话的东西都接起来，实验者问参加座谈会的人说哪一句话的解释是讲话的人心里想的意思。“结果完全是随机的，”米勒回忆说。“奥利佛·莱希（发难者）很是惊讶，竟然没有人看出在他看来十分明显的意思。乔姆斯基无动于衷，他早就知道实验会得出什么结果。” 智力发育：研究者们设计了许多比皮亚杰更好的一些实验方法，多半是单调乏味的，可有时候也有创造性的方法。如前所述，这些方法的确得出了极为重大的修正意见，还有一些是对他的部分工作的全盘否定。一些例子如下： ——小到4个月的婴儿的心率在一个物体消失时会加快，这个物体又回来时也是一样，这表明有了惊讶感。它说明，与皮亚杰的理论相反的是，婴儿期望物体继续存在。（可是，它们在物体消失后会立即忘掉这个东西，这一点依然是正确的。） ——皮亚杰曾就“数字守恒”测试过孩子（就是认识能力，比如说，六个排得很近的东西跟排得很开的六个东西数字是一样的。）他的结论是，除非孩子们到了约7岁时的具体操作阶段，否则他们不能获得这个认识。可是，最近，一些研究者们利用了不同的一些实验方法，如罗克尔·格尔曼的“魔术”法。在这种方法中，实验人员把一块板上的一组玩具老鼠偷偷拿走一只，或者偷偷增加一只，这些动作都是在用布盖着板的时候进行的。5岁甚或更小些的孩子能够分辨出多了或者少了，而且还会说，增加或者拿走了一只。 ——一些研究孩子们采取别人的观点的研究者利用了比皮亚杰更为自然的一些方法。他们不问一些东西从不同的角度看上去是什么样子，而是让孩子们与不同的人谈话，讲出他们对玩具工作原理的理解。令人吃惊的是，连4岁的小孩也会使用一些较短的简单句子与两岁的孩子谈话，而与成人谈话时却使用较长和复杂一些的句子。很明显，学龄前儿童比较不那么以自我为中心，也比皮亚杰所认为的更有能力站在另一个人的立场上。 ——皮亚杰说，孩子是在几年的时间内慢慢获得对因果关系的理解的。后来的研究者们说，他之所以得出这个结论，是因为他请孩子们解释是什么东西引起风和雨的，机器怎么工作的，以及其它一些超出他们的能力范围的问题。如果人们请他们回答一些他们很熟悉的问题，其结果可能不一样。在这样一次实验中，孩子们看见一个球在一只大盒子里顺着一个坡滚下去，然后不见了，这个时候，盒子里藏着的一只玩具娃娃跳出来了。然后，这只实际上由两部分构成的盒子被拉开了，原来在盒子的另一半中看着滚走的球很明显不能够跑到盒子的另一半里面去，可是，玩具娃娃还是从里面跳出来了。这时候，4-5岁的孩子们会大笑起来，他们吱吱地笑着，身体扭动着，并说出像“这是玩的把戏，是吧”？很清楚，他们感觉这事情按理不能发生的。 --若干心理学家们以大量实验为基础提出，人类智力成长不是以分界很清楚的阶段完成的，不像皮亚杰所描述的那个样子。有很多互相重叠或者逐渐的变化，而不是他的模型所描述的样子。还有证据证明，有时候，孩子能在完全掌握他那个阶段的能力前完成——或者经过训练后完成——某些较高级的心理任务。心理发展步骤的顺序并非一成不变的。再说，孩子经过训练以后，有时候可以思考超过他们目前的阶段的问题。 因此，许多发展心理学家虽然一方面接受皮亚杰总体的智力发展理论，可是，他们现在认为，他的阶段论太生硬了，而且有限。安大略教育研究学的罗比·凯斯已经掌握了大量证据以支持他自己雄心勃勃的四阶段论，这四个阶段都有四个平等的子阶段。这只是许多尝试中的一个，大家都想重构皮亚杰的结构，这样，它就可以容纳30年来许多极有价值的发现。目前，哪一种理论会流行起来还是个疑问。可以在认知发展心理学中处于统治地位的理论将会象征皮亚杰的基本概念，可它会远远超过皮亚杰理论，就像爱因斯坦的理论象征了，但远远超过牛顿物理学一样。 从头到尾的发展 发展心理学最新的潮流在四个世纪以前就已经初现端倪了。就是由所有外行心理学家中感觉力最为灵敏的一个人提出来的，他就是威廉·莎士比亚。跟皮亚杰和他的跟随者们不一样，莎士比亚在《皆大欢喜》一剧著名的独白“世界是一个大舞台”中，提出了一种整个一生和比较不那么理想化的图景，而皮亚杰却认为发展是在少年期以前就已经大部完工的工作。在独白中，雅克提出了人生的“7岁”，从“婴儿，／在乳姆的双臂中咪咪叫，吐奶”开始，最后到“返老还童，然后毫无感觉，／牙齿没有了，老眼昏花，食不甘味，什么都没有了”。 早在20年代，一些心理学家就开始认为发展是人一生持续不断的过程了。这时候，如前面所述的好几项重大的实验已经开始。可是，他们的目标主要是要衡量在几年时间内的变化，而不是检查产生这些变化的过程。然而，1950年，心理分析学家和发展心理学家埃里克·艾里克松首次提出了终生发展的详细过程模型，他的基础是他自己对一些主要的心理社会挑战的分析，这些挑战在生命的八个阶段的每一个阶段都面对着这个人，还有这些挑战所带来的那些变化。 艾里克松（1902-）虽然从来没有得到过高等院校的学位，可是，他在五十多年的时间内一直是在这个国家极受尊敬的发展心理学家之一，并在好几所著名大学担任过教授职位。他父母是丹麦人，信清教的父亲在艾里克松还没有出生的时候就离开他的犹太母亲了，后来，她就嫁给了一位德意志-犹太族儿科医生。艾里克松两头都不是人，在学校，他因为是犹太人而受人耻笑，在犹太会堂他又被讥笑为犹太异教分子，因为他长得金发碧眼。这样的经历让他对在发展过程中通过斗争来达到自我认识发生了兴趣。 在他的青年时代，艾里克松学习过艺术，并作为画家工作过几年，可在罗马的旅行中，他仔细看过米开朗基罗的作品，再考虑他自己的作品，突然间有了一阵强烈的自卑感和焦虑，竟致于跑到维也纳去找安娜·弗洛伊德对自己进行心理分析了。结果他不仅排遣了焦虑，而且树立了一个新的目标：他研究心理分析，并成了业余的分析师。 当纳粹于1933年在德国上台后，艾里克松同妻子先移民到丹麦，然后到了美国。他以心理分析行医，在哈佛大学、耶鲁大学和芝加哥大学教书（最终回到了哈佛大学），在贝克莱大学参加过一些纵向研究活动，与人类学家一起呆过一阵子，调查过两种美国土著文化。从他自己多种多样的经历中，他感觉到人类的发展是一项终生的活动，在这些发展过程中，人会经历一系列心理斗争，每项斗争都有生命各个阶段的特点，每种都会被新知识的获取和性格的发展所解决。 第一个阶段，即婴儿期的中心议题是基本的信任与不信任之间的冲突。在与有爱心的父母的关系中，婴儿解决了这个危机，学会了理解互相依靠和相亲相爱，并得到了信任。在第二个阶段，即儿童时期的早期，这期间的斗争是孩子对一种自理的需要与怀疑及羞耻感之间的矛盾。如果让孩子在合适的指导之间体验自由选择和自我控制，孩子会通过学习规则的重要性而解决危机，并获取自我控制或者意志。就这样，每一个阶段都代表一种危机，每一个阶段都会增加一些性格，长此以往，如果每个阶段的过渡都平稳的话，孩子就会使自己与社会达成更大的调和。 下面就是艾里克松的终生发展观。每个阶段都比前一个阶段更高一级。 1.婴儿期：基本信任对基本不信任／信任 2.儿童早期：自理对羞耻／意志及独立 3.游戏阶段：自发对内疚／目的 4.上学阶段（6-10岁左右）：勤奋对自卑／能干 5.少年期：身份对角色混乱／自我感觉 6.成年早期：私密性对隔离／爱 7.成年中期：生殖与停滞／关心别人；事业有成 8.老年：自我完整对绝望／智慧；完整的感觉，足以抵挡生理退化。 如果不能平稳地渡过任何一个阶段，正常的健康发展就会受阻。比如，一个没有人关心和爱护的婴儿也许永远不能学会信任别人，这是一种缺失，它会影响或者扭曲以后的一些发展阶段。一位少年，如果他的父母对他管束太严，也许不能顺利通过第五阶段，不能获得独立的身份感，结果一方面会成为“长不大的孩子”，另一方面可能会反骨丛生。 艾里克松的理论在发展心理学向生命周期观点的转变中起了非常大的作用。造成这种转变的另一个重要影响，是几十年来一直就在进行之中的许多重要的纵向研究所提供的大量生命周期数据。第三个影响是二战后那批处于“生育高峰”期的人从儿童向青年及中年的过渡，以及随之而来的65岁这批人口的增加，这两种因素都迫使社会科学工作者和立法者把注意力集中到有中年及老年特点的一些变更和问题上来。 向生命周期观点的转变，在50年代慢慢地开始了，在60年代有所抬头，在70年代成了绝对的潮流。在这10年当中，哥伦比亚大学洛衫机医学院的罗杰·L·古尔德在好几篇文章中理出了成人生命阶段发展的理论。达塔毛斯大学的心理分析师乔治·E·维伦在《适应生命》一书中也做了类似的事情。耶鲁大学的心理学家丹尼尔·J·利文森在《男人生命的四季》中如法炮制；作家盖尔·希茜把这些信息通过她的畅销书《转折：成人生活可预测的危机》传达给了大众。到1980年，尽管大部分发展心理学研究仍然还在处理生命早期的一些问题，可是，发展在整个生命中以阶段的形式进行的观点已经深入人心，成了发展心理学的主导范式，也成了文人圈中的共同观点。 目前的生命周期发展论与艾里克松的观点不一样，前者是多元论的，它要解决发展的所有方面，而不仅仅是心理社会方面。它解释一个阶段一个阶段的变化，从性格、社会关系、到从生物学影响的角度看到的认知、与年龄相关的心理变化以及社会及环境影响，这些变化与特定的年龄相关，也与那些可能在任何年龄产生的东西相关。再说，艾里克松乐观的看法是，正常和健康和发育是向上发展的，而最近几年最为流行的全生命周期发展论的音调是，实证主义的，是实打实的现实主义。它认为，成人阶段之后的发展是一系列变化，而不是一种向上的持续运动，它是对变化的现实而不是过程的适应。 这并不是说，今天的全生命过程发展论就是悲观的，说真的，它的有些发现还是令人鼓舞的。这里有几个例子。 少年期：有关少年期阶段的许多新资料涉及一些熟悉的话题：性行为、社会发育、挣脱父母的约束而获取自我解放、有关自我形象和焦虑等的问题。可是，长期以来，人们一直认为少年期是一阵内部混乱，可是，好几种最新研究却提出了相反的意见，认为在少年期的大部分时间内情形并非如此。一项研究报告说，虽然百分之十一的少年有严重的周期性麻烦，百分之三十二的少年有间歇性、条件性的问题，可是，百分之五十七的人“在少年时代的早期基本上是良好和健康的发育”。虽然吸毒、嗜酒、抽烟和性行为在少年时期有所增多，并引起部分少年严重的麻烦，可是，一个研究小组说，这些行为更多情况下是“故意的、自我调节的，旨在对付发育的问题”。 成人“危机”：成人发展研究的中心一直就集中在男女都必须实现的紧张转换，特别是在约40-45岁的时候，这时，他们也许认为自己的事业已经到顶了，梦想褪去了色彩，孩子们开始远离家庭，朝气蓬勃的身体也开始走下坡路了。流行作家希茜称这种情况为“可预见的危机”；大部分研究者却把这些叫做痛苦和费神的“转换期。” 一个小组发现，只有一些男人才有中年危机，其中的大部分人要么兴旺发达，要么胡乱应付。其它一些小组发现，成人性格并非一成不变，坚不可摧的，并非像以前所认为的那样完全由儿童时期的经历所决定。许多成年人可以作出足够多的适应以成功转向新的生活环境。如保尔·默森及合著者在《心理发展：全生命周期的探索》中所言：“也许，对性格和老年最为重要的研究结果，就是重新认识到了性格可以在生命的任何时期得到改变。” 老年：老年发展变化早已成为一代人的研究领域，在过去的15年中还是一个主要的研究领域。大部分研究集中于由走下坡路的生理能力、慢性病、心理功能的减缓、退休、离异独处、朋友的去世和其它损失带来的心理变化。对于这样一些变化，在50年代晚期于堪萨斯城进行的老年研究的基础上，广为接受的一种看法是，共同和有益的适应是“脱钩”——放弃有压力的一些角色以减轻压力，自愿退入“老年子文化圈。”可是，由心理学家罗伯特·J·哈维格斯特及其同事对堪萨斯城的资料进行的重新分析，再加上在杜克大学进行的一项25年的纵向老年研究都显示，情况并非如此。有些人选择了脱钩，而另外一些人却是因为身体不好而被迫如此的，可是，大部分老年人还在坚持他们的社会活动，并适应了忍受亲朋好友的故去，他们扩大接触范围，与年轻人，特别是家人多多接触。再说，他们大部分人都比那些脱了钩的人更满足，心理更健康。 几十年来，心理学家曾测量过不同年龄层次的智商，并发现了在成人向老年生活的转化当中出现了稳定的智商下降。可是，发展论方法显示，这是测试引起的人工结果，而不是现实。老一辈人接受的教育普遍较少，与测试的经验也少些，年轻的一辈两者机会都多些。在长时期内测试和重新测试同一批人的纵向研究发现，在70岁以前并没有明显的智力减退，而有些人，只在80岁以后才有一些并不严重的减退，只要他的大脑没有得病，或者没有其它严重的身体毛病。 在中年晚期和以后，许多人抱怨自己的记忆力减退了，而最新的研究显示，大部分人在50岁以后，其记忆力的确有缓慢的下降。尽管这使很多有记忆力减退毛病的人大为吃惊，可是，这都是正常的现象，并不是说一定就会得阿尔兹海默氏病。这只是轻微的变化，直到80岁以后才有可能变得严重起来，而且在大多数情况下，都是可以通过助记术和其它一些方法的使用，减除过量的药物使用来加以改善的。 发展心理学也许看上去完全成熟了。它包容了人类的一生，对变化的原因采取了更广泛的看法，也有充足的证据证明，发育的确是一个阶段一个阶段地进行的。 尽管如此，这个研究领域仍然处于一种无序的状态。有不止一种阶段论，至少有十几种主要的理论，还有更多的次要理论。这些理论在某些方面是共同的，而在另外一些地方又彼此不同。生命周期发展心理学实际上不是一种察看受试者的理论，它是一种方法，可以同时容纳和综合不同的理论。也许，它永远也不能超出这个范畴，如在本章多次说过的一样，发展心理学是如此广泛的一个领域，它可能需要一连串的理论而不是一种总括一切的理论。 这并不是说要诋毁发展心理学，自然科学的王后物理学就有同样的限制。许多物理学家都相信，有一种理论可能解释物理学中的四种力（原子核里面的强力、约束某些粒子的弱力、电磁力和引力），可是，从来没有人能够形成这样一种理论。也许根本就没有这样一种理论。或者，也许任何统一性的解释都会超出思维之眼的范围，就像无线电波是人眼本身所不能看见的一样。 当心理学还是哲学家们所考虑的问题时，各种理论看上去都能解释一切；当它成为一门科学时，已经很难构架总括一切的理论了。很明显，这个领域越是科学，人类能够设计一种无所不包的解释性心理学理论的可能性就越小，哪怕在心理学中最大的分支——发展心理学中亦是如此。