Bachelor of Education Notes, All Universities Across World, Topi: INDIVIDUAL DIFFERENCES

INDIVIDUAL DIFFERENCES

DEFINITION: Individual differences are the variations from one person to another on variables such as self-esteem, rate of cognitive development or degree of agreeableness. Historically, psychological science has overlooked individual differences in favor of focusing on average behavior. The differences between individuals that separate them from one another and make one as a unique individual in oneself are termed as individual differences.

That people differ from each other is obvious. How and why they differ is less clear and is the subject of the study of Individual differences (IDs). Although to study individual differences seems to be to study variance, how are people different, it is also to study central tendency, how well can a person be described in terms of an overall within-person average. Indeed, perhaps the most important question of individual differences is whether people are more similar to themselves over time and across situations than they are to others, and whether the variation within a single person across time and situation is less than the variation between people. A related question is that of similarity, for people differ in their similarities to each other. Questions of whether particular groups (e.g., groupings by sex, culture, age, or ethnicity) are more similar within than between groups are also questions of individual differences.

Personality psychology addresses the questions of shared human nature, dimensions of individual differences and unique patterns of individuals. Research in IDs ranges from analyses of genetic codes to the study of sexual, social, ethnic, and cultural differences and includes research on cognitive abilities, interpersonal styles, and emotional reactivity. Methods range from laboratory experiments to longitudinal field studies and include data reduction techniques such as Factor Analysis and Principal Components Analysis, as well as Structural Modeling and Multi-Level Modeling procedures. Measurement issues of most importance are those of reliability and stability of Individual Differences.

Research in Individual Differences addresses three broad questions: 1) developing an adequate descriptive taxonomy of how people differ; 2) applying differences in one situation to predict differences in other situations; and 3) testing theoretical explanations of the structure and dynamics of individual differences.

Taxonomies of individual differences:

Taxonomic work has focused on categorizing the infinite ways in which individuals differ in terms of a limited number of latent or unobservable constructs. This is a multi-step, cyclical process of intuition, observation, deduction, induction, and verification that has gradually converged on a consensual descriptive organization of broad classes of variables as well as on methods for analyzing them. Most of the measurement and taxonomic techniques used throughout the field have been developed in response to the demand for selection for schooling, training, and business applications.

Personality and Ability

Although to some the term personality refers to all aspects of a person's individuality, typical usage divides the field into studies of ability and personality. Tests of ability are viewed as maximal performance measures. Ability is construed as the best one can do on a particular measure in a limited time (speed test) or with unlimited time (power test). Personality measures are estimates of average performance and typically include reports of preferences and estimates of what one normally does and how one perceives oneself and is perceived by others.

The same procedures used to clarify the structure of cognitive abilities have been applied to the question of identifying the domains of personality. Many of the early and current personality inventories use self-descriptive questions (e.g., do you like to go to lively parties; are you sometimes nervous) that are rationally or theoretically relevant to some domain of interest for a particular investigator. Although there is substantial consistency across inventories developed this way, some of this agreement could be due to conceptually overlapping item pools. Other researchers have advocated a lexical approach to the taxonomic problem, following the basic assumption that words in the natural language describe all important individual differences. This shifts the taxonomic question from how are individuals similar and different from each other to how are the words used to describe individuals (e.g., lively, talkative, nervous, anxious) similar and different from each other.

Dimensional analyses of tests developed based on lexical, rational, or theoretical bases suggest that a limited number (between three and seven) of higher order trait domains adequately organize the thousands of words that describe individual differences and the logically infinite way that these words can be combined into self or peer report items. The broadest domains are those of introversion-extraversion and emotional stability-neuroticism, with the domains of agreeableness, conscientiousness and intellectual openness or culture close behind. These domains can be seen as asking the questions that one wants to know about a stranger or a potential mate: are they energetic and dominant (extraverted), emotionally stable (low neurotic), trustworthy (conscientious), loveable (agreeable), and interesting (intelligent and open). Measures of ability and personality reflect observations aggregated across time and occasion and require inferences about stable latent traits thought to account for the variety of observed behaviors. However there are other individual differences that are readily apparent to outside observers and require little or no inference about latent traits. The most obvious of such variables include sex, age, height, and weight. Differences that require some knowledge and inference are differences in ethnicity and social economic status. These obvious group differences are sometimes analyzed in terms of the more subtle measures of personality and ability or of real life outcomes (e.g, sex differences in neuroticism, mathematics ability, or income).

Predictive Validity

Individual differences are important only to the extent that they make a difference. Does knowing that people differ on a trait X help in predicting the likelihood of their doing behavior Y? For many important outcome variables the answer is a resounding yes. In their review of 85 years of selection in personnel psychology, Frank Schmidt and John Hunter (Psychological Bulletin, 1998, 124, 262-274) show how differences in cognitive ability predict differences in job performance with correlations averaging about .50 for mid complexity jobs. These correlations are moderated by job complexity and are much higher for professional-managerial positions than they are for completely unskilled jobs. In terms of applications to personnel psychology, a superior manager (one standard deviation above the mean ability for managers) produces almost 50% more than an average manager. These relationships diminish as a function of years of experience and degree of training. General mental ability (g) also has substantial predictive powers in predicting non-job related outcomes, such as likelihood of completing college, risk for divorce and even risk for criminality.

The non-cognitive measures of individual differences also predict important real life criteria. Extraversion is highly correlated with total sales in dollars among salespeople. Similarly, impulsivity can be used to predict traffic violations. Conscientiousness, when added to g substantially increases the predictability of job performance. Although the size of the correlation is much lower, conscientiousness measured in adolescence predicts premature mortality over the next fifty years.

Sources of individual differences

The taxonomic and predictive studies of individual differences are descriptive organizations of thoughts, feelings, and behaviors that go together and how they relate to other outcomes. But this categorization is descriptive rather than causal and is analogous to grouping rocks in terms of density and hardness rather than atomic or molecular structure. Causal theories of individual differences are being developed but are in a much earlier stage than are the descriptive taxonomies.

Descriptive taxonomies are used to organize the results of studies that examine genetic bases of individual differences. By applying structural modeling techniques to the variances and co-variances associated with various family constellations it is possible to decompose phenotypic trait variance into separate sources of genetic and environmental variance. The most common family configurations that are used are comparisons of identical (monozygotic) with fraternal (dizygotic) twins. Additional designs include twins reared together or apart, and biological versus adoptive parents, children and siblings. Conclusions from behavioral genetics for most personality traits tend to be similar: Across different designs, with different samples from different countries, roughly 40-60% of the phenotypic variance seems to be under genetic control with only a very small part of the remaining environmental variance associated with shared family environmental effects. Additional results suggest that genetic sources of individual differences remain important across the lifespan. However, this should not be taken to mean that people do not change as they mature but rather that the paths one takes through life are similar to those taken by genetically similar individuals.

Genes do not code for thoughts, feelings or behavior but rather code for proteins that regulate and modulate biological systems. Although promising work has been done searching for the biological bases of individual differences it is possible to sketch out these bases only in the broadest of terms. Specific neurotransmitters and brain structures can be associated with a broad class of approach behaviors and positive affects while other neurotransmitters and structures can be associated with a similarly broad class of avoidance behaviors and negative affects. Reports relating specific alleles to specific personality traits emphasize that the broad personality traits are most likely under polygenic influence and are moderated by environmental experience.

Subtle differences in neurotransmitter availability and re-uptake vary the sensitivity of individuals to cues about their environment that predict future resource availability and external rewards and punishments. It is the way these cues are detected, atttended to, stored, and integrated with previous experiences that makes each individual unique. Current work on the bases of individual differences is concerned with understanding this delicate interplay of biological propensities with environmental opportunities and constraints as they are ultimately represented in an individual's information processing system. With time we can expect to increase our taxonomic and predictive power by using these causal bio-social theories of individual differences.

Importance of individual differences

Individual differences are essential whenever we wish to explain how individuals differ in their behavior. In any study, significant variation exists between individuals. Reaction time, preferences, values, and health linked behaviors are just a few examples. Individual differences in factors such as personality, intelligence, memory, or physical factors such as body size, sex, age, and other factors can be studied and used in understanding this large source of variance. Importantly, individuals can also differ not only in their current state, but in the magnitude or even direction of response to a given stimulus. Such phenomena, often explained in terms of inverted-U response curves, place differential psychology at an important location in such endeavours as personalized medicine, in which diagnoses are customised for an individual's response profile.

What is the difference between individual differences variables and manipulated variables?

An individual difference variable are variables that occur naturally and that a researcher cannot assign a participant to. These include gender, age, height, etc. A manipulated variable a researcher can assign a person to such as a placebo group vs. the actual medicine. An individual difference is any difference in the way in which people behave or think. For example, IQ and memory capabilities would be individual differences as these values vary between people.

Kohlberg's Theory of Moral Development

BIOGRAPHICAL INTRODUCTION

An outstanding example of research in the Piagetian tradition is the work of Lawrence Kohlberg. Kohlberg has focused on moral development and has proposed a stage theory of moral thinking which goes well beyond Piaget's initial formulations. Moral development is a major topic of interest in both psychology and education. One of the best known theories was developed by psychologist Lawrence Kohlberg who modified and expanded upon Jean Piaget's work to form a theory that explained the development of moral reasoning.

Piaget described a two-stage process of moral development, while Kohlberg's theory of moral development outlined six stages within three different levels. Kohlberg extended Piaget's theory, proposing that moral development is a continual process that occurs throughout the lifespan.

"The Heinz Dilemma"

Kohlberg based his theory upon research and interviews with groups of young children. A series of moral dilemmas were presented to these participants and they were also interviewed to determine the reasoning behind their judgments of each scenario.

The following is one example of the dilemmas Kohlberg presented"

Heinz Steals the Drug 

"In Europe, 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 woman's husband, Heinz, went to everyone he knew to borrow the money, but he could only get together about $ 1,000 which is half of what it cost. 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 discovered the drug and I'm going to make money from it." So Heinz got desperate and broke into the man's store to steal the drug-for his wife. Should the husband have done that?" (Kohlberg, 1963). Kohlberg was not interested so much in the answer to the question of whether Heinz was wrong or right, but in the reasoning for each participant's decision. The responses were then classified into various stages of reasoning in his theory of moral development.

Level 1. Preconventional Morality

• Stage 1 - Obedience and Punishment
  
  The earliest stage of moral development is especially common in young children, but adults are also capable of expressing this type of reasoning. At this stage, children see rules as fixed and absolute. Obeying the rules is important because it is a means to avoid punishment.
• Stage 2 - Individualism and Exchange
  
  At this stage of moral development, children account for individual points of view and judge actions based on how they serve individual needs. In the Heinz dilemma, children argued that the best course of action was the choice that best-served Heinz’s needs. Reciprocity is possible at this point in moral development, but only if it serves one's own interests.

Level 2. Conventional Morality

• Stage 3 - Interpersonal Relationships
  
  Often referred to as the "good boy-good girl" orientation, this stage of moral development is focused on living up to social expectations and roles. There is an emphasis on conformity, being "nice," and consideration of how choices influence relationships.
• Stage 4 - Maintaining Social Order
  
  At this stage of moral development, people begin to consider society as a whole when making judgments. The focus is on maintaining law and order by following the rules, doing one’s duty and respecting authority.

Level 3. Postconventional Morality

• Stage 5 - Social Contract and Individual Rights
  
  At this stage, people begin to account for the differing values, opinions and beliefs of other people. Rules of law are important for maintaining a society, but members of the society should agree upon these standards.
• Stage 6 - Universal Principles
  
  Kolhberg’s final level of moral reasoning is based upon universal ethical principles and abstract reasoning. At this stage, people follow these internalized principles of justice, even if they conflict with laws and rules.

Criticisms of Kohlberg's Theory of Moral Development:

• Does moral reasoning necessarily lead to moral behavior? Kohlberg's theory is concerned with moral thinking, but there is a big difference between knowing what we ought to do versus our actual actions.
• Is justice the only aspect of moral reasoning we should consider? Critics have pointed out that Kohlberg's theory of moral development overemphasizes the concept as justice when making moral choices. Factors such as compassion, caring and other interpersonal feelings may play an important part in moral reasoning.
• Does Kohlberg's theory overemphasize Western philosophy? Individualistic cultures emphasize personal rights while collectivist cultures stress the importance of society and community. Eastern cultures may have different moral outlooks that Kohlberg's theory does not account for.

PIAGET'S STAGES OF MORAL JUDGMENT

Piaget studied many aspects of moral judgment, but most of his findings fit into a two-stage theory. Children younger than 10 or 11 years think about moral dilemmas one way; older children consider them differently. As we have seen, younger children regard rules as fixed and absolute. They believe that rules are handed down by adults or by God and that one cannot change them. The older child's view is more relativistic. He or she understands that it is permissible to change rules if everyone agrees. Rules are not sacred and absolute but are devices which humans use to get along cooperatively.

At approximately the same time--10 or 11 years--children's moral thinking undergoes other shifts. In particular, younger children base their moral judgments more on consequences, whereas older children base their judgments on intentions. When, for example, the young child hears about one boy who broke 15 cups trying to help his mother and another boy who broke only one cup trying to steal cookies, the young child thinks that the first boy did worse. The child primarily considers the amount of damage--the consequences--whereas the older child is more likely to judge wrongness in terms of the motives underlying the act (Piaget, 1932, p. 137).

There are many more details to Piaget's work on moral judgment, but he essentially found a series of changes that occur between the ages of 10 and 12, just when the child begins to enter the general stage of formal operations.

Intellectual development, however, does not stop at this point. This is just the beginning of formal operations, which continue to develop at least until age 16. Accordingly, one might expect thinking about moral issues to continue to develop throughout adolescence. Kohlberg therefore interviewed both children and adolescents about moral dilemmas, and he did find stages that go well beyond Piaget's. He uncovered six stages, only the first three of which share many features with Piaget's stages.

KOHLBERG'S METHOD

Kohlberg's (1958a) core sample was comprised of 72 boys, from both middle- and lower-class families in Chicago. They were ages 10, 13, and 16. He later added to his sample younger children, delinquents, and boys and girls from other American cities and from other countries (1963, 1970).

The basic interview consists of a series of dilemmas such as the following:

Heinz Steals the Drug

In Europe, 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 woman's husband, Heinz, went to everyone he knew to borrow the money, but he could only get together about $ 1,000 which is half of what it cost. 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 discovered the drug and I'm going to make money from it." So Heinz got desperate and broke into the man's store to steal the drug-for his wife. Should the husband have done that? (Kohlberg, 1963, p. 19)

Kohlberg is not really interested in whether the subject says "yes" or "no" to this dilemma but in the reasoning behind the answer. The interviewer wants to know why the subject thinks Heinz should or should not have stolen the drug. The interview schedule then asks new questions which help one understand the child's reasoning. For example, children are asked if Heinz had a right to steal the drug, if he was violating the druggist's rights, and what sentence the judge should give him once he was caught. Once again, the main concern is with the reasoning behind the answers. The interview then goes on to give more dilemmas in order to get a good sampling of a subject's moral thinking.

Once Kohlberg had classified the various responses into stages, he wanted to know whether his classification was reliable. In particular, he. wanted to know if others would score the protocols in the same way. Other judges independently scored a sample of responses, and he calculated the degree to which all raters agreed. This procedure is called interrater reliability. Kohlberg found these agreements to be high, as he has in his subsequent work, but whenever investigators use Kohlberg's interview, they also should check for interrater reliability before scoring the entire sample.