The Psychology of Individual Differences addresses the description, prediction and explanation of inter-individual, inter-group and intra-individual variability in relevant psychological areas, with respect to its origin, manifestation, and functioning.
Description Requires the following steps: Observation and evaluation in representative samples, both of the population under study and of the universe of behaviors to be studied. Classification and ordering of the dimensions found, based on the correlational methodology, in taxonomies, or structuresorganizational.
Object and objectives
The most important initial question for the study of individual differences is to detect (Revelle):
- If people are more like themselves, over time and situations, than they are like other people
- If the single individual varies less, across time and situations, than the variation that occurs between people.
Prediction The dimensions found in the different areas of research present an important predictive value in very varied criteria of people’s lives, academic, work, or family and social relationships. Explanation It requires knowing the nature, how they work, and what processes they entail in order to develop theories of an explanatory nature. Sources of human variability The analysis of the nature of individual differences refers us to the study of the existing sources of variation.
Following Revelle (1995) regarding the levels of analysis and explanation in behavioral diversity, we distinguish three sections:
- Psychological variability is the primary object of study of the discipline and refers to the differences that exist in all manifestations of human behavior: As far as the structure of individual differences is concerned, we will talk about the feature as a fundamental unit for the study of psychological variability, while, from a more current study of individual differences based on the study of operating dynamics of these traits we will pay greater attention to the processes of intrapsychic dynamics and to relevant situational factors, beyond classical personal dispositions, or traits.
- Biological variability Hypothesis: The genetic and biological bases of individual differences are the origin of the existing variability, at least as far as some fundamental dimensions are concerned. Two types of basic research: the percentage of the phenotypic variance of behavior that is explained by the differences in the genetic endowment of individuals and the variation explained based on the differential functioning of biological mechanisms. On the other hand, the advances that have been produced around “quantitative genetics” and more specifically “behavioral genetics” form a solid foundation on which to build new “interactionist” explanations.
Currently, it is completely assumed that genes do not set behavior, they only specify a range of possibilities in the reactions that the environment provokes in the individual.
The goal of behavioral genetics It will be to investigate the ultimate causes of the differences between individuals, taking as reference the phenotypic variance observed in a behavioral trait. But neither the method used by behavioral genetics is adequate to provide causality to intergroup differences, nor can the results achieved through it constitute an explanatory basis in favor of genetic determinism of group differences. .
In any case, whether from the framework of “behavioral genetics” or “molecular genetics”, the results indicate the importance of experiential differences between individuals, a facet in which there is a deficiency of adequate measures, which limit the formulation of models and theories that, in a coherent and systematic way, can predict behavioral differences. There are some conceptual frameworks, such as sociobiology and its derivation most closely linked to psychology, evolutionary theory, that aim to find the key that articulates the influences of biological and environmental variability, however such theories develop in a degree of abstraction that makes it difficult to achieve scientific verification of their arguments. On the other hand, as Revelle points out, genes do not act directly on behavior.
The second line of research on the sources of biological variation focuses on the study of the biological foundations of differential human behavior based on physiological structures and processes governed by fundamental systems such as the Nervous System (central and autonomic), the Neuroendocrine system, etc. As far as intelligence is concerned, practically all biological models could be grouped around the hypothesis that “at the heart of intelligence is the brain” and, therefore, that the bases of mental ability will be based on neurophysiology, articulated around “the neural efficiency model”which says that more intelligent people present a series of biological correlates that show greater mental efficiency and speed.
Techniques such as evoked potentials, nerve conduction velocity, or measurement of brain glucose are among the most used (Davidson and Downing). In personality, the model proposed by Eysenck and Eysenck bases the Extraversion/Introversion dimension on cortical arousal and the ascending cerebral reticular system, and Neuroticism on the limbic system. Other authors have proposals of a temperamental nature. In the opinion of Pervin and John, the relationships between personality and biological processes continue to be a problematic issue at the beginning of the 21st century. c. Situational and cultural variability Since evolutionary theory proposed combining the relatively random genesis of variability in living organisms with the directional role of natural selection that acts from the interaction between individuals and the demands of the environment, the joint importance of genetics and environment in determining variability in behavioral patterns.
Galton himself, so interested in hereditary factors, he assumed the influence of these factors through the notion of relative consistency. Situational factors have never been excluded from the psychological consideration of human variability. Subsequently, the influence of modern “interactionism” allowed us to overcome the controversy between “personalism” and “situationism”, emphasizing that what is important about the situation is not the physical attributes of the situation, but, above all, its significance for the subject, which leads us, again, to variability. psychological.
Levels of complexity of contextual variables depending on their degree of generality and temporal persistence (according to Endler): the stimulus: refers to the specific objects on which the subject directs his attention and response. the situation: that acquires the character of an organized whole that integrates various components. the environment: which groups together a variety of situations and the relationships between them. Ten Berge and De Raad have made a distinction between situational concepts based on the theoretical perspectives to which they can be assigned: the ecologicalwhich emphasizes the physical elements of the environment; the behavioralwhich focuses its attention on the value stimulate of the situation; and the psychological-socialwhich serves the roles and the symbolic elements of the social episodes in which the behavior takes place.
In general, two ways of approaching the analysis of situations have been differentiated: A priori elaboration of situational taxonomies: it is useful to achieve a systematic analysis of the objective characteristics that define situations and their influence on behavior; although the problem that this strategy presents is the notable lack of agreement both in the proposed classifications and in the criteria underlying them. Characterization of the specific contexts where the behavior occurs: such contexts are referred, in the broadest sense, to the Ecological system in which the person is immersed and even the observer of the same. In this sense, for more than thirty years approaches have also been emerging that, trying to achieve an integrative vision of the environment, propose a certain articulation of the objective and subjective facets of the environment. A very clear example of this is the concept of “social climate”, which means that each environment has a unique “personality” and underlying patterns of environmental dynamics that can be considered similar to those that make up the personal system, so that Both systems in “interaction” give rise to individual differences.
Comprehensive view of the sources of variability
As Sánchez Cánovas defends, the psychology of individual differences is not deterministic, but random. When talking about genetics or inheritance, we refer to what is given, not to a determination. One of the characteristics that define the reflexivity of the human being is its purposefulness or behavioral intentionality. Most integration attempts take as their starting point either Bertalanffy’s “general systems theory” or “information processing theory”, two theoretical frameworks of different origin but that coincide in their generality and complexity. when approaching the study of human behavior, and that have paved the way to achieve organization and provide coherence to the data from different research in the psychology of individual differences.
Others Approaches have been aimed, in recent years, at clarifying the way in which genetic and environmental factors interact when exerting their influence on intellectual manifestations. Ceci proposes a bioecological model of intelligence that emphasizes multiple cognitive potentials, together with the role of context and knowledge, as the bases of individual differences in cognitive performance. Scarr, supported by the three types of genotype-environment relationship, passive, active and reactive, has highlighted the notion of “construction of a niche”, within an evolutionary theory of individuality, which implies that as they mature , individuals seek, construct and create environments that correspond to their inherited personal characteristics, in which to develop their personality, their interests and their abilities.
Relevant constructs in individual differences research
Currently, integrative theories proliferate in which the uniqueness of the individual takes priority, trying to describe, predict and explain their behavior from a broad framework that includes the systematization of both cognitive, emotional and motivational variables. to. Intelligence Of…