Traditionally, individual differences in intelligence and personality have been studied under distinct paradigms. Intelligence is typically conceptualized and measured as “peak performance,” while personality is conceptualized and measured as “typical performance” (Goff & Ackerman, 1992). Intelligence is assessed using tests designed to determine a person's maximum mental capacity. Tests are typically administered under strict administrative procedures to create an environment of high situational strength that will limit environmental or contextual factors. A person taking an intelligence test is told that there is only one correct answer to each question and the importance of doing your best is emphasized. In contrast, personality assessments are designed to measure behavioral tendencies in a wider variety of contexts. Personality traits are usually measured using self-report questionnaires in which the respondent is informed that there is no right or wrong answer and asked to answer honestly. Items are not rated as “correct” or “incorrect,” but rather on a bidirectional scale (e.g., Likert scale). This suggests that these constructs should be studied separately given their critical differences with respect to theory and measurement, an approach to the study of personality-intelligence associations that has been referred to as the "independence approach" (Chamorro -Premuzic and Ackerman, 2011).Say no. to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an Original Essay However, substantial theoretical and empirical progress has been made in the study of the intersection between personality traits and intelligence (DeYoung, 2011). The expansion of the literature on personality-intelligence associations, which began both with broad research exploring trait correlations and progressed to specific theories hypothesizing a small set of relationships between traits (Ackerman and Heggestad, 1997), eventually gave rise to intellectual “investment traits.” ". Investment traits are defined as “stable individual differences in the tendency to continually seek out, engage in, take advantage of, and pursue opportunities for demanding cognitive activity” (von Strumm, et al., 2011). Such traits are generally more correlated with crystallized intelligence than with fluid intelligence (Goff & Ackerman, 1992; Funmham. Monsen, & Ahmetoglu, 2009; Judge et al., 2007; von Strumm & Ackerman, 2013). This article provides a historical review of the development of these investment characteristics. I begin by reviewing work that preceded the theoretical foundation of investment traits, but which: a) provided commentary or theorizing that intelligence is not simply an inherited ability by recognizing the role of non-ability factors, or b) included broad investigations of personality and abilities. associations. Next, I review two critical developmental theories that provide the theoretical backbone of investment traits and three of the most frequently used investment traits and their psychometric measurement scales. Finally, I conclude by discussing the growing field of intellectual investment and the broad impact that investment traits have had on the field of psychology, both historically and today.Early work leading to theoretical development investment traitsintellectualEarly empirical studies suggesting personality-intelligence associations were very broad in scope and the literature subsequently converged on a smaller number of traits that play an important role in intellectual development (Ackerman & Heggestad, 1997). The early 20th century was characterized by such extensive research, one of the first being the dissertation of Edward Webb (Webb, 1915). As a student of Charles Spearman, Webb supported Spearman's theory of general intelligence (g) (Spearman, 1904). For his dissertation, Webb designed a study in which he asked experienced students to assessed students less advanced in an educational program on a wide variety of abilities and personality traits over the course of a semester and used factor analysis to isolate a general factor of intelligence. and a general “character” factor (i.e., non-ability factors). The results suggest two aspects of mental processes: intelligence and character. While Webb viewed these factors as distinct and used an orthogonal rotation in his analysis, he observed that ratings of intelligence and character were correlated and attributed this to bias on the part of raters toward students they viewed positively . The important aspect of this study for the purposes of this article is its general nature – Webb reported that these two general factors appeared to be related (albeit due to scoring bias) but did not discuss a small number of specific traits that play an important role. role. This is a representative example of early studies of personality-intelligence associations that did not include the precision of later studies in history. The idea that personality traits are linked to intellectual ability also dates back to the beginnings of differential psychology. Lewis Terman is well known not only for the development of the Stanford-Binet intelligence test (Terman, 1916), but also for his longitudinal study of gifted children. Terman identified approximately 1,500 children with substantial abilities, whom he called “Termites,” and selected them based on an IQ cutoff of 140 (Terman, 1922; Terman & Fenton, 1921). He launched a large-scale longitudinal study in which he followed them throughout their lives and collected a significant amount of psychological measurements. When monitoring gifted children, Terman included an assessment of what he called “intellectual traits” (Terman & Oden, 1959, as cited in von Strumm & Ackerman, 2013). The assessment asked parents and teachers to rate the four students on four different aspects of personality: desire for knowledge, general intelligence, originality and common sense. Although this is one of the first mentions of personality traits linked to intelligence, it is worth pointing out that Terman did not use a personality trait "specific to the investment personality space" (von Strumm and Ackerman, 2013). There were two other early personality traits. contributions that were important in laying the foundations for theoretical developments that led to the development of intellectual investment traits. The first was presented in William McDougall's book describing his theory of dynamic psychology (McDougall, 1932). McDougall believed that natural instincts guided human behavior and that this premise was the central theme of his book. He identified 18 different intrinsic "propensities" that motivate human behavior: foraging, disgust, sex, fear, curiosity, protective/parenting, gregarious, assertive, submissive, anger, calling, constructive, acquisitive, laughing, comforting , rest./sleep, migratory and bodily needs. McDougall argued that no behavior is purely intellectual, but that all forms of behavior rely on one or more of these instinctive propensities. He gave the hypothetical example of a starving rat in a cage with food attached to a string connected to a piece of lead on the other side of the cage, leaving the food hanging in the air. The rat gets the food by pulling the string. McDougall argued that although many psychologists consider this behavior intellectual, it is not solely about intelligence, because the propensity to forage determines this behavior. In other words, animal and human behavior is “both instinctive and intelligent” (McDougall, 1932, p. 67). Although McDougall's argument does not specifically involve personality traits, his theory recognizes the role of tendencies outside the realm of abilities that impact behavior and this idea was developed by later theories that had an impact for the literature on intellectual investment traits. The second contribution that led psychologists toward theories suggesting the influence of personality traits on intelligence came from Keith Hayes (1962). Similar to McDougall, Hayes argued that intelligence was linked not only to natural abilities, but also to natural propensities for behavior. However, Hayes took the idea a step further by asserting that intelligence is uniquely determined by genetic differences in "experience-producing drives" which in turn lead to differences in the knowledge that individuals accumulate. Similar to McDougall, Hayes offered a hypothetical example to illustrate his point. If two fraternal twins growing up in the same environment differ in their interests, such that one twin is oriented toward language activities such as speaking and reading and the other is oriented toward physical activities such as sports, it is very possible that the linguistic activity oriented twin will score higher on the Stanford Binet in adolescence than the physical activity oriented twin simply because he developed a larger vocabulary by reading and speaking more frequently. Hayes bases his proposition that intelligence is the result of drive-producing experiences on four related arguments: 1) differences in motivation are genetically based, 2) differences in motivation lead to different experiences, 3) experiential differences lead to differences in abilities, and 4) differences in intelligence are nothing more than differences in acquired abilities. Hayes uses a variety of evidence to support these arguments, including research on learning and memory, evidence from brain-damaged adults, and a lack of statistical evidence on "higher mental functions." Ultimately, he concludes that "innate intellectual potential consists of tendencies to engage in activities conducive to learning, rather than inherited abilities." (Hayes, 1962). Although Hayes does not mention specific personality traits, his theory suggests that intelligence is more than an inherited ability and that the willingness to engage in different types of activities influences the knowledge humans acquire throughout life. of their lives. Subsequent theoretical contributions built on the work of Hayes and McDougall to develop comprehensive theories of intellectual investment that paved the way for the development of scales measuring personality traits that lead to the acquisition of knowledge and skills . the sectionPrevious work emphasized the idea that non-ability factors play a role in the depth and breadth of knowledge or skills acquired throughout life and included large empirical investigations suggesting associations between personality and intelligence, none addressing specific theories involving the role that non-ability factors play. Personality traits play a role in the development of intelligence. In this section, I review two developmental theories that are central to the conceptual understanding of investment characteristics. Raymond B. Cattell's "Investment Theory of Intelligence" is perhaps the most critical theory for the development of investment traits. Cattell introduced a hierarchical theory of intelligence with two factors at the broadest level: fluid intelligence and crystallized intelligence (Cattell, 1963). Fluid intelligence involves process-related abilities, such as novel problem solving, abstract thinking, memory, and flexible thinking, that peak in the early 20s and then decline throughout life. Crystallized intelligence involves content-related knowledge, including factual knowledge, vocabulary, and understanding that increases or is maintained across the lifespan (Horn & Cattell, 1966, 1967). Cattell's investment theory discusses the relationship between fluid and crystallized intelligence. The theory proposes that investing in fluid intelligence eventually gives rise to crystallized intelligence. We use more and more knowledge or skills. Cattell referred to a relationship between fluid abilities and the accumulation of knowledge in a 1943 Psychological Bulletin article when he stated that "crystallized ability consists of long-established discriminatory habits in a particular domain, originally by the functioning of the fluid ability, but no longer requiring insight. perceptual for their successful operation” (Cattell, 1943). He later expanded this idea by proposing the formal theory in his book titled Intelligence: Its Structure, Growth, and Action Cattell (1971/1987). In his book, Cattell offers an example that illustrates the relationship he proposes between fluid and crystallized intelligence. A student learning to solve algebra problems first uses his fluid intellectual abilities, but over time, as he becomes familiar with the methods used to solve the problem, it becomes a crystallized intelligence as he uses procedural knowledge already acquired rather than engaging in a new problem. -solve. If this premise is true, a person's current crystallized capacity is a function of the "operational levels" of their fluid intelligence in previous years. According to Cattell, individual differences outside the realm of ability impact what and how much people invest their fluid intelligence in. what they do. He argues that this is why Spearman observes a general intelligence factor. This is not because a person's vocabulary impacts their ability to solve math problems, but because people who invest more of their fluid intelligence perform better on everyone's tests. This is especially true in early educational settings where there is a standardized curriculum. The correlations between different abilities and knowledge decrease as one specializes in a particular subject or profession. In a later chapter of his book, Cattell proposes..