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Introduction
Individual DifferencesâThen and Now
Every man is in certain respects: a. like all other men, b. like some other men, c. like no other man.
(Kluckhohn & Murray, 1948, p. 35)
Though the language employed in our opening quote betrays its origins in a very different era, Kluckhohn and Murrayâs (1948) classic observation remains valid today. The notion that people differ from, and have things in common with, each other is hardly new or revelatory; it is something immediately obvious to anybody who has ever interacted with more than two human beings. Accordingly, a well-developed strand of psychologyâdifferential psychology or, as it has been recently more frequently referred to, individual difference (ID) researchâ has been concerned with understanding those characteristics that make individuals dissimilar to each other, exploring how and why such differences occur. This matter is related to one of the fundamental issues underlying the whole domain of psychology as an academic discipline. Ever since the early days of its existence, psychology has been trying to achieve two different and somewhat contradictory objectives: to understand the uniqueness of the individual mind and to explore the general principles of the human mind; in Barrettâs (2006, p. 35) words, âThe goal of psychology is to discover the scientifically viable constructs or categories that will characterize what is variant and invariant in the working of the human mind.â Individual difference research, then, has been focusing on the former area: inter-individual variation.
In this chapter we will first introduce the concept of IDs and describe the âclassicâ perspective on it; in doing so, we hope to present a strong case that understanding learner variation is an essential part of the study of second language acquisition (SLA) in general. Then, after we have set the scene, we will turn to some of the problems that have emerged regarding the traditional conceptualization of ID variables and which have resulted in the transitional stage regarding the status of individual differences that characterizes the field today. Finally, we conclude the chapter by discussing new angles to the understanding of learner characteristics that may offer viable future directions for research.
The Classic Perspective on Individual Differences
As the term suggests, individual differences are characteristics or traits in which individuals may be shown to differ from each other. Admittedly, for many scholars such differences constitute mere distractions to their work: How much easier it would be to formulate valid conclusions and generalizations about the human species if everybody was alike! Research results would then apply to everyone and, based on these findings, we would be able to design effective therapy or intervention that would suit all. Thus, in this ideal world ârules and regulations could be developed to cover all situations, and there would be no unknownsâ (Breslin, 1994, p. 224). Alas, although the distinctness that each of us displays may be seen by some as a nuisance, it is still thereâand the world is surely a better place for it. In fact, one of the most important ways in which the social sciences differ from the natural sciences stems exactly from the existence of individual differences: The molecules of a cell, if treated identically, will respond identically, whereas human behaviorâeven that of identical twinsâmay vary significantly in response to a certain stimulus.
IDs are seemingly easy to define: They concern anything that marks a person as a distinct and unique human being. While this may appear by and large trueâparticularly if we adopt a broad conception of IDsâwe need to set some restrictions to avoid regarding, for example, someoneâs tendency to wear a brightly colored T-shirt or a bow tie as an ID. Therefore, all scientific definitions of IDs assume the relevance of stability, and this notion of stability will feature as a key consideration as we attempt to reconceptualize IDs within SLA later in the book. Differential psychology emphasizes individual variation from person to person only to the extent that those individualizing features exhibit continuity over time (Cervone & Pervin, 2013). Yet, even with this restriction, the kind and number of ways by which an individual can be different is extensive because of the innumerable interactions between heredity and environment that occur throughout oneâs life span. Although a specific consideration of the ânature or nurtureâ debateâthat is, whether individual differences are due to heredity or environmental influencesâis outside the scope of this book (see e.g., Dale, Harlaar, & Plomin, 2012), questions of how inherited genetic information and interaction with the environment (Anastasi, 1994) may limit or facilitate individual achievement are central to our discussion.
So, can the term individual differences be further narrowed? It can and it has been: The majority of books and articles dealing with the subject tends to cover fewer than a dozen ID factors. This is because the actual practice of differential psychology does not focus on mere idiosyncrasies, even when these are stable ones, but rather on broader dimensions that (a) are applicable to everyone and (b) discriminate among people (Snow, Corno, & Jackson, 1996). As Michael Eysenck (1994) summarized it very clearly,
Although human beings differ from each other in numerous ways, some of those ways are clearly of more significance to psychology than others. Foot size and eye color are presumably of little or no relevance as determinants of behavior (although foot size may matter to professional footballers!), whereas personality appears to play a major role in influencing our behavior.
(p. 1)
Thus, the classic ID construct refers to dimensions of enduring personal characteristics that are assumed to apply to everybody and on which people differ by degree. Or, in other words, it concerns stable and systematic deviations from a normative blueprint. We should note that these descriptions do not resolve the basic dilemma of the scientific study of human differences, namely the question of how to conceive of general laws or categories for describing human individuality that at the same time do justice to the full array of human uniqueness. Placing ID research in a historical context is a useful first step in exploring this dilemma further.
A Brief History of Individual Difference Research
In their account of the historical development of differential psychology, Revelle, Wilt, and Condon (2011) explain that understanding how people differ from each other, and then applying that knowledge, is a pursuit that has occupied human society for much of its recorded history. They identify passages in ancient textsâfor example, the Old Testament or classical Greek literature such as Platoâs The Republicâthat grapple with some of the fundamental concerns of differential psychology. However, in order to discover the origins of modern ID research we need to go back no further than the end of the 19th century: Charles Darwinâs cousin, Sir Frances Galton (1822â1911), is usually credited with being the first to investigate individual differences scientifically, and Galtonâs empirical and methodological research, which also involved developing appropriate statistical techniques for data analysis, is also seen as the genesis of quantitative psychology in general. Following Galton, ID research was firmly and irreversibly put on the research agenda at the turn of the century by the work of French psychologist Alfred Binet (1857â1911). He became interested in individual differences partly as a result of his observations of the different ways his daughters solved problems, and his 1895 article co-authored by Victor Henri on âindividual psychologyâ was the first systematic description of the aims, scope, and methods of the topic. The real impetus to further research was given by the construction of the first intelligence test by Binet and his colleague Theodore Simon, and ever since the publication of this instrument in 1905, intelligence research and measurement theory have driven the study of individual differences forward.
The Binet-Simon intelligence scale was devised to separate slow and fast learners in the French school system, and adaptations were soon prepared for use in Germany and Britain. The popularity of intelligence testing spread quickly as the potential use of intelligence measures for selection and recruitment procedures was recognized. In the first half of the 20th century several other ability tests were developed and employed, and significant advances were made in statistics to provide analytical techniques to process and evaluate the test scores, making up what is commonly referred to as the classical testing theory (see Kline, 2005). This theory was then applied to the design of tests of personality, attitudes, specific cognitive aptitudes, and other psychological constructs.
The first listing of virtually all differential characteristics was constructed by Gordon Allport and Henry Odbert in 1936: They collected 17,953 descriptive words from an English dictionary and argued that each of these potentially suggested an individual difference variable. During the subsequent decades this extensive, and frankly unmanageable, list has been condensed by others to the key variables that are discussed currently under the ID rubric (for further details on identifying a parsimonious set of personality traits, see Chapter 2). The field rapidly gained momentum and by the 1950sâthe era that Revelle et al. (2011) suggest may represent the âhigh point of differential psychologyââit had generated enough empirical research on cognitive, affective, and psychomotor characteristics for Anne Anastasi to prepare her seminal summary, Differential Psychology, in 1958. With ongoing developments in the study of personality, motivation, and various cognitive abilities, ID research is still a powerful area within psychology, having its own society, the International Society for the Study of Individual Differences, and dozens of academic journals targeting either individual differences in general (e.g., Personality and Individual Differences and Learning and Individual Differences) or some specific ID factor (e.g., Intelligence). The importance of IDs has also been widely recognized in educational contexts and a great deal of research has been conducted in educational psychology on how to adapt instruction to the strengths, weaknesses, and preferences of learners.
Individual Differences in Second Language Studies
It has been long observed that there is a particularly wide variation among language learners in terms of their ultimate success in mastering an L2 and therefore the study of IDsâespecially language aptitude and language learning motivationâhas been a featured research area in SLA studies. Despite the fact that bilingualism, not monolingualism, is the norm in many, if not most, parts of the world, the capacity to acquire a second language to a high level of proficiency is not considered universal (we explore the links between L1 and L2 learning in more detail in Chapter 3). Schumann (2013) provides an evolutionary explanation for how we may have arrived at this situation, exploring the connections between the individual, the environment, and language. He argues that since almost everybody masters a first language with little difficulty, we can assume that there must have been some evolutionary advantage associated with the acquisition of language, and as a result, the ability to master a first language was genetically transmitted to future generations, ultimately becoming a universal human characteristic. In contrast, in the earliest forms of human settlement there was probably little intergroup contact that would have made the capacity to learn languages an imperative, and indeed, the widespread learning of foreign languages appears to be a relatively recent human endeavor, largely stimulated by increased population mobility and the spread of mass education. This being the case, we should not be surprised to find that serious consideration of the ways in which individuals differ in their language learning has a relatively short history.
Although various L2 learner characteristics had been investigated earlier, the real momentum in studying IDs within SLA came in the wake of the influential research on âgood language learnersâ in the mid-1970s (Naiman, Fröhlich, Stern, & Todesco, 1978; Rubin, 1975; for a retrospective review, see Griffiths, 2008). The results of this line of inquiry highlighted in general the significance of IDs as key factors that make L2 learners excel, and they indicated in particular that besides language aptitude and motivationâ which had been known to affect L2 learning successâthere were further important learner variables fostering L2 attainment, most importantly the studentsâ own active and creative participation in the learning process through the application of individualized learning techniques. Thus, language learning strategies were included in the inventory of important learner characteristics, and Peter Skehanâs (1989) seminal book on the subject, Individual Differences in Second Language Learning, also added learning styles to the âcanonicalâ list of IDs in language learning.
We may characterize the initial wave of ID research in SLA, centered around Skehanâs canon, as a quest to first identify those learner characteristics that have the most significant effect on learning outcomes and then to analyze the specific effects of particular characteristics. Dewaele (2009, 2012a) describes this quest as a holy grail approach because it was motivated by the underlying belief that âsome hidden internal characteristic of the L2 learner predetermines a more or a less successful outcomeâ (2012a, p. 159), and therefore uncovering this single source was hoped to unlock the doors to effective learning. Although not everybody went so far as to assign IDs any holy grail significance, it was widely acceptedâand the 2005 version of our book fully reflected thisâthat ID factors were powerful background learner variables with potential make-or-break quality, affecting different aspects of the acquisition process: Motivation was seen to underlie the direction and magnitude of learning behavior in terms of the learnerâs choice, intensity, and duration of learning; language aptitude concerned the cognitive dimension, referring to the capacity and quality of learning; learning styles were related to the manner of learning; and learning strategies were somewhere in between motivation and learning styles by referring to the learnerâs proactiveness in selecting specific made-to-measure learning routes. Thus, the composite of these variables was seen to answer why, how long, how hard, how well, how proactively, and in what way the learner engaged in the learning process.
Challenges to the Classic ID Paradigm
What is wrong, one may ask, with the seemingly straightforward conceptualization of ID factors described above? As Dörnyei (2009b) has argued, the intuitively convincing classic ID paradigm rests on (at least) four assumptions: (a) IDs exist as distinctly definable psychological constructs; (b) IDs are relatively stable attributes; (c) different IDs form relatively monolithic components that concern different aspects of human functioning and that are therefore only moderately related to each other; and (d) IDs are learner-internal, and thus relatively independent from the external factors of the environment. Since the publication of the original version of our book, however, serious issues have been raised about each of these four assumptions. As we shall argue below brieflyâand then in more detail in the following chaptersâwhen we look more closely, individual learner characteristics are not stable but show salient temporal and situational variation, and neither are they distinct and monolithic but involve, instead, complex constellations made up of different parts that interact with each other and the environment synchronically and diachronically. Murphey and Falout (2013) sum up the changing perspective well when they describe the current ID research agenda as one that portrays IDs as âsocially interdependent, malleable states developing over time.â This view is a far cry from the static, trait-like representation located inside the individual that is so often implied in everyday parlanceâfor example, when we say that Rupert is motivated or Gertrude has a low language aptitude. Let us start exploring the new emerging paradigm by focusing on two key issues, context and time.
The Question of Context and Time
In an analysis of SLA, Ellis and Larsen-Freeman (2006, p. 563) reflected on the issues of context and time as follows: âTo attribute causality to any one variable (or even a constellation of variables) without taking time and context into account is misguided.â This conclusion is in line with the outcome of a longstanding dispute in psychology, the âperson-situation debate,â concerning the extent to which the individualâs experience in the social environment affects aspects of human functioning, including language acquisition and use. Although in this matter the secret often lies in the details (for a discussion, see Leary & Hoyle, 2009), Funderâs (2006) conclusion reflects an emerging consensus:
Since at least the 1930s, deep thinkers as diverse as Allport (1937) and Lewin (1951) have argued that invidious comparisons miss the point because behavior is a function of an interaction between the person and the situation. By the 1980s this recognition had deteriorated into a truism. Nowadays, everybody is an interactionist.
(p. 22)
The question of situatedness also emerged as one of the central issues regarding IDs in the ...