Summary As a science, psychology uses systematic methods to observe, describe, predict, and explain behavior. Scientific methods are not casual. Researchers carefully and precisely plan and conduct their studies (Elms, Kantowitz, Roediger, 2003). In psychology, it is desirable to obtain results that describe the behavior of many different people. For example, researchers might construct a questionnaire on sexual attitudes and give it to 500 individuals. They might spend considerable time devising the question and determining the backgrounds of the people chosen to participate in the survey. The researchers may try to predict the sexual activity of college students based on their liberal or conservative attitudes or on their sexual knowledge, for example. After the psychologists have analyzed their data, they also will want to explain why and change in behavior occurred. They might ask, "Is the reason an increased fear of sexually transmitted diseases?" Because psychologists use the same research methods as physicists, biologists, and other scientists, psychology is a scientific discipline. In 1859, Darwin published his ideas in on the origin of Species. He proposed the principle of natural selection, an evolutionary process that favors organisms that are best adapted to reproduce and survive. He believed that organisms reproduce at rates that would cause enormous increases in the population of most species, yet noted that populations remain nearly constant. Darwin reasoned that an intense, constant struggle for food, water, and resources must occur among the young born in each generation, because many of the young do not survive. Those that do survive to adulthood pass their genes on to the next generation. Darwin concluded that organism with biological features that led to more successful reproduction was better represented in subsequent generations. Over the course of many generations, organisms with these characteristics would constitute a larger percentage of the population. Eventually this process could modify a whole population. If environmental conditions changed, however, other characteristics might become favored by natural selection, moving the process in a different direction. Freuds (1917) theory was the basis for the therapeutic technique that he termed psychoanalysis. His approach was controversial when he introduced it in Vienna at the beginning of the twentieth century. However, his ideas flourished, and many clinicians still find value in his insights about human behavior.

Although Darwin introduced the theory of evolution by natural selection in the middle of the nineteenth century, his ideas about evolution only recently became a popular framework for explaining behavior. One of psychologys newest approaches, the evolutionary psychology approach emphasizes the importance of adaptation, reproduction, and "survival of the fittest" in explaining behavior. Evolution favors organisms that are best adapted to survive and reproduce in a particular environment. The evolutionary psychology approach focuses on the conditions that allow individuals to survive or survive of fail. In this view, natural selection favors behaviors that increase the organisms reproductive success and ability to pass its genes to the next generation. Pennebakers personal experience led him to ask whether this theory of catharsis should perhaps be modified. For example, to experience the benefits of emotional release was it really necessary to talk to a psychotherapist? (After all, therapists can be expensive!) In fact, was it really necessary to be speaking to anyone at all? Could people with emotional troubles achieve the same relief by writing? And could people actually improve their physical health simply by writing about their problems? To explore these ideas further, Pennebaker needed to express his questions in more specific and concrete terms. He began by developing a hypothesis that he could test through concrete, objective observations. For example, exactly what did he mean by "writing about emotions"? Also, what did he mean by "physical health"? He needed to translate these ideas into operational definitions. An operational definition is an objective description of how a research variable is going to be observed and measured. Operational definitions eliminate some of the fuzziness and loose ends that easily creep into thinking about a problem. By being very specific about what measurements define concepts, operational definitions also clarify concepts for other scientists. The second step of the scientific method is to actually collect research information (data). Among the important decisions to be made about collecting data are whom to choose as the participants and which research methods to use. I explore a number of research methods in some detail shortly, so I focus here on the research participants. When psychologists conduct a study, they usually want to be able to draw conclusions that will apply to a larger group of people (or animals) than the participants they actually study. Thus an investigator might conduct a study of 300 married couples in Los Angeles, California, in which the

husband shows a history of abusing the wife, but the researcher may have the goal of applying the results to all married couples with a history of wife abuse in the United States. The entire group about which the investigator wants to draw conclusions is the population. In this particular study of spousal abuse, the population is all couples in the United States in which men abuse their wives. The subset of the population chosen by the investigator for study is a sample. In this spousal abuse study, the sample is the 300 couples in Los Angeles. By surveying a sample of the population, the researcher avoids the difficulties involved in trying to find and survey all American husbands who abuse their wives. The target population to which the investigator wants to generalize varies with the study. For example, in a study of the effects of televised violence of boys aggression, the population might be all 3 to 5 year old boys in the United States. In a study of how people think critically, the population might be all humans. In a study of whether chimpanzees have language, the population might be all chimpanzees. Generalization from the sample to the population can be made only if the sample is representative or "typical" of the population. For example, a disproportionate number of the 300 couples in the study o f spousal abuse might have income in the poverty range and be Anglo Americans. We would have to be cautious about generalizing the results of this study to the entire American population of couples in which the husbands abuse their wives, especially to such couples in higher income brackets and from other ethnic groups. For observations to be effective, they have to be systematic (Leary, 2001). We have to have some idea of what we are looking for. We have to know whom we are observing, when and where we will observe, and how the observations will be made. And in what from will they be recorded? In writing? Tape recording? Video? Laboratory research does have some drawbacks. First, it is almost impossible to conduct research without the participants knowing they are being studied. Second, the laboratory setting is unnatural and therefore can cause the participants to behave unnaturally. A standard set of questions id used to obtain peoples self-reported attitudes or beliefs about a particular topic. In a good survey, the questions are clear and unbiased, allowing respondents to answer unambiguously. A Case study, or case history, is an in depth look at a single individual. Case studies are performed mainly by clinical psychologists when, for either practical or ethical reasons, the unique aspects of an individuals life cannot be duplicated and tested in other individuals (Dattilio, 2001). A case

study provides information about one persons fears, hopes, fantasies, traumatic experiences, upbringing, family relationships, health, or anything that helps the psychologist understand the persons mind and behavior. For example, we could have observed Pennebaker during the period of his deep depression and used our observations as the basis of a case study. The degree of relationship between two variables is expressed as a numerical value called a correlational coefficient. Lets assume that we have data on the relationship between how long your instructor lectures (the X variable) and the number of times students yawn (the Y variable). For the sake of this example, lets assume these data produce a correlation coefficient (represented by the letter r) of +. 70. Remember this number, as it will soon be used to illustrate what a correlation coefficient tells you about the relationship between two events or characteristics. For the moment, however, you need to know only that the number tells you the strength of the relationship between the two factors. The rule is simple: the closer the number is to 1.00, the stronger the correlation; conversely, the closer the number is to .00, the weaker the correlation. Figure 2.2 offers guidelines for interpreting correlational numbers. But perhaps you are wondering about the significance of the plus sign in the correlation coefficient of +. 70 that we have calculated in our classroom study. If the behavior under study changes when a factor is manipulated, we say that the manipulated factor has caused the behavior to change. In other word, the experiment has demonstrated cause and effect. The cause is the factor that was manipulated, and the effect is the behavior that changed because of the manipulation. Non-experimental research methods (descriptive and correlational research) cannot establish cause and effect because they do not involve manipulating factors in a controlled way. Experiments have two types of changeable factors, or variables: independent and dependent. An independent variable is a manipulated, influential, experimental factor. It is a potential cause. The label independent is used because this variable can be manipulated independently of other factors to determine its effect. Researchers have a vast array of options open to them in selecting independent variables, and one experiment may include several independent variables (Shaughnessy, Zechmeister, Zechmeister, 2003). The mean is not so helpful, however, when a group of scores contains a few extreme scores. Consider the annual earnings for the two groups of five

people shown in the table that follows. Group I lists the earnings of five ordinary people. Group 2 is composed of the earnings of four ordinary p people plus the approximate earnings of movie director Steven Spielberg. Now look at the means that have been calculated for the two groups. The vast difference between them is due to the one extreme score. In such a situation, one of the other two measures of central tendency, median or mode, would give a more accurate picture of the data overall. The median is the score that falls exactly in the middle of the distribution of scores after they have been arranged (or ranked) from highest to lowest. When you have an odd number of scores (say, 5 or 7 scores), the median is the score with the same number of scores above it as below it. In the table, each group has a median income of $23.000. Notice that, unlike the mean, the median is unaffected by extreme scores. The medians are the same for both groups ($23.000), but their means are extremely different ($22.000 versus $9.017.000). Of course, if there is an even number of scores, there is no "middle" score. This problem is dealt with by averaging the scores that "share" the middle location. The mode is the score that occurs most often in a set of data. In our present example, the mode is $19.000, which occurs twice in each group. All of the other annual incomes occur only once. The mode is the least used measure of central tendency. The mode can be useful, for example, in cases in which information is desired about preference or popularity. Consider a teacher who wants to know the most popular or least popular child in her classroom. She might create a questionnaire and ask students which of their classmates they like the most or the least. The most frequently nominated child would be the mode in these instances. In addition to revealing the central characteristics of a sample, statistics can also give us measures of variability, which describe how much the scores in a sample vary from one another. Imagine that you are the owner of three computer stores that all have the same annual earnings of $1.200.000. However, these three stores fluctuate widely in their monthly earnings. Store 1 consistently produces a monthly income of about $10.000. Store 2 generates no income some months but produces $200.000 of income in other months. Store 3 loses money the first 9 months of every year but makes enormous profits during October, November, and December. You would be correct in saying that the mean annual earnings of each of your stores are $1.200.000. But business planning would be easier if you could also represent the individual fluctuations in the earnings of your three stores. Measures of variability can be very helpful in this regard.

Notice that all three joggers had the same mean race time of 40 minutes. But jogger 1 and jogger 3 each had race times that varied from race to race, whereas jogger 2 had exactly the same time for each of the four races. This variability from race to race, or the lack of in, is expressed by the three different standard deviations. Because jogger 2 had no variability from race to race, that persons standard deviation is 0. Jogger 1s race time varied 4 minutes on the average from his mean of 40 minutes. (Calculate the difference between each joggers mean time and race time, and then divide by the four races.) In other words, jogger 1 had a standard deviation of 4 minutes for his race times. Jogger 3s race times varied 8 minutes on the average from her mean time of 40 minutes. Thus, jogger 3 had a standard deviation of 8 minutes for her race times. The different standard deviations tell you that jogger 2 had no variability among his race scores, jogger 1 had some variability among his race scores, and jogger 3 had even more variability among her race scores. Thus the standard deviation tells you how consistently each jogger performed. A word of caution is in order about interpreting statistical significance. A statistically significant difference in a research study does not always translate into a difference that has meaning in everyday life. Before assuming that a finding is significant both statistically and in everyday life, it is wise to examine the actual differences involved. For example, in comparisons of average scores for males and females on the Scholastic Assessment Test, the difference is statistically significant (Benbow, Stanley, 1983). In other words, the difference Physical processes involve changes in an individuals biological nature. Genes inherited from parents, the hormonal changes of puberty and menopause, and changes throughout life in the brain, height and weight, and motor skills all reflect the developmental role of biological processes. Psychologists refer to such biological growth processes as maturation. Zhang Liyin has a body build and exceptional motor skills that allow her to perform well in gymnastics. Genes play in important role in human behavior; genes alone do not determine who we are. Genes exist within the context of a complex environment that is necessary for an organism to even exist. Environment includes all of the surrounding physical and social conditions and influences that affect the separating the effects of Biologists who study even the simplest animals agree that separating the effects of the animals genes from the effects of their environment is virtually impossible (Lewis, 2003).

Genetic material may be expressed differently depending on the environment. Thus a persons observable and measurable characteristics might not reflect their genetic heritage very precisely because of the experiences they have had. Some psychologists believe we can develop beyond what our genetic inheritance and our environment give us. They argue that a key aspect of development involves seeking optimal experiences in life (Massimini, Dell Fave, 2000). They cite examples of people who go beyond simple biological adaptation to actively pick and choose from the environment the things that serve their purposes. These individuals build and construct their own lives, authoring a unique developmental path. Occurs when individuals adjust their schemas to new information. That is, people accommodate their schemas to the environment. For example, a child might possess the schema of "picking up". With experience, the child might learn that some things can be picked up easily between two fingers, that other things might require both hands and strong use of the arms, and that still other things cannot be picked up at all because they are too hot, for example, or too heavy. Thus the schema "picking up" becomes modified into different schemas that accommodate the realities of different types of objects. Piaget believed that "out of sight" literally was "out of mind" for young infants. At 5 months of age, you would not have reached for the monkey when it fell behind the hippopotamus. By 8 months of age, though, infants begin to understand that out of sight is not out of mind. At this point, you probably would have reached behind the hippopotamus to search for the monkey, coordinating your senses with your movements. Overall, then, preoperational thought is more symbolic that sensorimotor thought, but it is egocentric and intuitive rather than logical, and it does not include the ability to perform operation. But in reaching a basic level of operational understanding, the child progresses to the third of Piagets cognitive stages. A woman was near death from a special kind of cancer. There was one drug that the doctors thought might save her. It was a form of radium that a druggist in the same town had recently discovered. The drug was expensive to make, but the druggist was charging ten times what the drug cost him to make. He paid $200 for the radium and charged $2.000 for a small dose of the drug. The sick womans husband, Heinz, went to

everyone he know to borrow the money, but they could get together only $1.000. He told the druggist that his wife was dying and asked him to sell it cheaper or let him pay later. But the druggist said, "No. I After reading the story, the interviewee was asked a series of questions about the moral dilemma. Should Heinz have stolen the drug? Was stealing it right or wrong? Why? Is it a husbands duty to steal a lifesaving drug for his wife if he can get it in no other way? Would a good husband do it? Did the druggist have the right to charge so much in the absence of a low setting a limit on the price? Why or why not? Based on the answers that people gave to the questions about this and other moral dilemmas, Kohlberg constructed a theory. At the post conventional level, the individual recognize alternative moral courses, explores the options, and then develops a personal moral code. The code reflects the principles generally accepted by the community (stage 5) or it reflects more abstract principles for all of humanity (stage at stage 5, a person might say that the law was not set up for these circumstances. So Heinz can steal the drug. It is not really right, but he is justified in doing it. At stage 6, the individual evaluates alternatives but recognizes that Heinzs wifes life is more important than a low. Trust versus mistrust occurs during approximately the first 112 years of life. Trust is built when a baby's basic needs such as comfort, food and warmth are met. If responsive, sensitive caregivers do not meet infants needs, the result is mistrust. Trust in infancy sets the stage for a lifelong expectation that the world will be a good and pleasant place to live. Initiative versus guilt occurs from 3 to 5 years of age, the preschool years. During these years, children's social worlds are widening, and they are being challenged to develop purposeful behavior to cope with the challengers. When asked to assume more responsibility for them, children can develop initiative. When allowed to be irresponsible or made to feel anxious, they can develop too much guilt. But Erikson believed that young children are resilient. He said that a sense of accomplishment quickly compensates for most quilt feeling. But researchers have questioned the importance of feeding in infant attachment. Harry Harlow (1958) separated infant monkeys from their mothers at birth and placed them in cages in which they had access to two artificial "mothers". One of the mothers was made of wire, the others of cloth. Each mother could be outfitted with a feeding mechanism. The wire mother, half by the cloth mother, fed half of the infant monkeys. The

infant monkeys nestled close to the cloth mother and spent little time on the wire one, even if it was the wire mother that gave them milk. This study clearly demonstrates that what the researchers described as "contact comfort", not feeding, is the crucial element in the attachment process. Their mother as soon as they hatched. But those in the second group, who saw Lorenz first after hatching, followed him everywhere as if he were their mother (see figure 4.15). Lorenz marked the goslings and then placed both groups under a box. Mother goose and "mother" Lorenz stood nearby as the box was lifted. Each group of goslings went directly to its "mother". Lorenz called this process imprinting, the tendency of an infant animal to form an attachment to the first moving object it sees and / or hears. For goslings, the critical period for imprinting is the first 36 hours after birth. Human infants appear to have a longer, more flexible "sensitive period" for attachment. A number of developmental psychologists believe that attachment to the caregiver during the first year provides an important foundation for later development. John Bowl by (1969, 1989), for instance, believes the infant and the mother instinctively form an attachment. He believes the newborn is innately equipped to stimulate the caregiver to respond: it cries, clings, smiles, and coos. Later the infant crawls, walks, and follows the mother. The infant's goal is to keep the mother nearby. Research on attachment supports Bowls view that the infants attachment to its caregiver intensifies at about 6 to 7 months. As both Sigmund Freud and the nineteenth century Russian novelist Leo Tolstoy observed, adulthoods two most important themes are work and love. The study of socioemotional development in the adult years largely bears them out. Psychologists have proposed different theories about adult socioemotioanl development. Most theories address themes of work and love, career and intimacy. But before examining what psychologists have learned about these themes, lets return to Eriksons stage theory of life span development. Career interests continue to be an important dimension of life for many middle aged adults. Midlife is a time at which many people examine what they have accomplished in their careers and become concerned about the limited amount of time remaining to accomplish what they want. However, many reach the highest satisfaction in their careers during middle age, and only about 10 percent of Americans change careers at midlife. Some change careers against their wills, of course: Middle aged adults may be forced to reexamine their career choices because of the downsizing

and early retirement programs at many companies that are experiencing financial troubles. Work defines individuals in fundamental ways (Osipow, 2000). People identify with their work, and the work shapes many aspects of their lives. It is an important influence on their financial standing, leisure activities, where they live, friendships, and health. Work also eats up big chunks of peoples time. In one recent survey, 35 percent of Americans worked 40 hours a week, but 18 percent worked 51 hours a week or more (Center for Survey Research, 2000). Only 10 percent worked less than 30 hours a week. Many myths also are associated with being single, ranging from the "swinging single" to the "desperately lonely, suicidal single." Most singles are somewhere between these two extremes. The pluses of being single include time to make decisions about ones life, time to develop personal resources to meet goals, freedom to make ones own decisions and pursue ones own schedule and interests, opportunities to explore new places and try out new things and privacy. Common problems of single adults include a lack of intimate relationship with others; loneliness, and feelings of being out of step in a marriage oriented society. Generalizing about singles is hard. Some single adults would rather remain single; others would rather be married. In his best selling book, the seasons of a mans Life, Daniel Levinson (1978) described the results of his extensive interviews with middle aged men in a variety of occupations: hourly workers, academic biologists, business executives, and novelists. Although Levinsons original participants were all men, he subsequently reported that the midlife issues he uncovered in his research affect women as well (Levinson, 1996). Levinson argued that, by age 40, people reach a stable point in their careers, outgrow their earlier, more tenuous status as adults, and begin to define the kind of lives they will lead in middle age. He believes the transition period is a time of crisis that lasts about 5 years. However, older adults may become more selective about more selective about their social networks, according to one theory (Carstensen, 1995, 1998). Because they place a high value on emotional satisfaction, older adults often are motivated to spend more time with familiar individuals close friends and family members with whom they have had rewarding relationships. They may deliberately withdraw from social contact with individuals on the fringes of their lives. This narrowing of social

interaction maximizes positive emotional experiences and minimizes emotional risks as individuals. (Lang & Carstensen, 1994, Lee & Markides, 1990). In learning the alphabet, you made some mistakes along the way, but at some point you learned all of your letters. You changed from some none who did not know the alphabet to someone who did. Learning anything new involves change. Once you learned the alphabet, it did not leave you. Once you learn how to drive a car, you do not have to go through the process again at a later time. If you ever decide to try out for the X Games, you may break a few bones along the way, but at some point you probably will learn a trick or two, changing from a novice to someone who can at least stay on top of a skateboard. Learning involves a relatively permanent influence on behavior. You learned the alphabet through experience with the letters some of you may have learned it by watching Sesame Street. Through experience, you also learned that you have to study to do well on a test, that there usually is an opening act at a rock concert, and that a field goal in American football adds 3 points to the score. Putting these pieces together, we arrive at a definition of learning: a relatively permanent change in behavior that occurs through experience. In classical conditioning, organisms learn the association between two stimuli. As a result of this association, organisms learn to anticipate events. For example, Lightning is associated with thunder and regularly precedes it (Purdy, others, 2001). Thus, when you see lightning, you anticipate that you will hear thunder soon afterward. In operant conditioning, organisms learn the association between a behavior and a consequence. As a result of this association, organisms learn to increase behaviors that are followed by rewards and to decrease behaviors that are followed by punishment. For example, children are likely to repeat their good manners if their parents reward them with candy after they have shown good manners. Also, if childrens bad manners are followed by a few nasty words and glances by parents, the children are less likely to repeat the bad manners. Stimulus generalization is not always beneficial. For example, the cat that generalizes from a minnow to a piranha has a major problem; therefore it is important to also discriminate between stimuli. Discrimination in classical conditioning is the process of learning to respond to certain stimuli and not to respond to others (Murphy, Baker, Fouquet, 2001). To produce discrimination, Pavlov gave food to the dog only after ringing the bell and

not after any other sounds. In this way, the dog learned to distinguish between the bell and other sounds. In positive reinforcement, the frequency of a behavior increases because it is followed by a rewarding stimulus. For example, if someone you meet smiles at you after you say, "Hello, how are you?" And you keep talking; the smile has reinforced your talking. The same principle of positive reinforcement is at work when you teach a dog to "shake hands" by giving it a piece of food when it lifts its paw. Other evidence to support the role of cognitive maps in learning was obtained in experiments on latent learning. Latent Learning is unreinforced learning that is not immediately reflected in behavior. In one study, two groups of hungry rats were placed in a maze and required to find their way from a starting point to an end point (Tolman & Honzik, 1930). The first group found food (a reinforce) at the end point; the second group found nothing there. In the operant conditioning view, the first group should learn the maze better than the second group, which is exactly what happened. However, when Tolman subsequently took some of the rats from the no reinforced group and gave them food at the end point of the maze, they began to run the maze as effectively as the reinforced group. The no reinforced rats apparently had learned a great deal about the maze as they roamed around and explored it. But their learning was latent, stored cognitively in their memories but not yet expressed behaviorally.