Intelligence and creativity have long been subjected to scientific studies on their correlation, yet there is still not one clear answer (Jauk, Benedek, Dunst, & Neubauer, 2013; Nusbaum & Silvia, 2011). Intelligence and creativity are two essential constructs that are highly valued in society, affecting the quality of living for humans, and resulting in phenomenal changes (Sligh, Conners & Ewoldsen, 2005). Various hypothesis emerged as a result to explain the relationship between the two mental constructs. The Threshold Hypothesis is one prominent and controversial hypothesis which states that creativity and intelligence are related up till a threshold, historically set at IQ = 120, where no further significant correlations exist (Karwowski & Gralewski, 2013; Jauk et al., 2013; Sligh et al. 2005). Empirical data from several studies differ in the confirmation of the Threshold Hypothesis (Karwowski & Gralewski, 2013); a possible explanation for the inconsistency in results is the lack of standardisation across the measure of intelligence and creativity (Kim, 2005). This essay aims to examine certain theories of intelligence and components of creativity, analyse the evidences for the validity of the Threshold Hypothesis, and evaluate alternative theories which explain the relationship between intelligence and creativity.
Various studies of the Threshold Hypothesis measure different factors of intelligence and creativity, hence it is imperative to visit certain theories of intelligence and look at components of creativity. Spearman (1927, as cited in Martin, Carlson, & Buskist, 2012) proposed that intelligence is determined by a general (g) factor and a task-specific (s) factor. Cattell and Horn (1966, as cited in Martin et al., 2012) further distinguished two factors of intelligence – fluid intelligence (gf) and crystallized intelligence (gc): Fluid intelligence refers to the ability to reason and relate ideas, it is not bound by cultural influences; crystallized intelligence refers to the utilizing of acquired knowledge to solve issues and is dependent on the cultural background. Level of intelligence is also largely represented by IQ (Martin et al., 2012). The studies on creativity measured creative potential/ability and creative achievement separately (Karwowski & Gralewski, 2013; Jauk et al., 2013); the level of creativity was generally tested by fluency – the number of ideas, and originality – the quality of ideas (Jauk et al., 2013; Cho, Nijenhuis, Vianen, Kim, & Lee, 2010). The studies on the Threshold Hypothesis measured different factors of intelligence and creativity, leading to inconclusive results on its validity. This is consistent with the explanation by Kim (2005) that the inconclusive result is due to inconsistency in the variables of intelligence and creativity measured.
The validity of the Threshold Hypothesis is supported by Jauk et al. (2013): The study found that “Intelligence significantly predicted creative potential in a lower IQ range but not in the upper IQ range” (p. 218). The test measured the correlation of general intelligence (g) with three components of creativity: fluency, originality and average originality (Jauk et al. 2013). While there was significance of a threshold effect, the points of IQ as threshold differed in the three variables of creativity. The threshold for fluency was at 86.09, originality at 104.00, and average originality at 119.60 IQ points. Jake et al. (2013) theorised that it is easier to produce more number of ideas than to produce good quality ideas, hence the disparity in the threshold IQ of 86 (fluency) and 104 (originality). Karwowski and Gralewski (2013) also found that a threshold effect was more consistently established at 115 IQ points instead of the unsubstantiated historically-set threshold point at 120 IQ points. The authors focused on the correlation of gf to creative abilities and established three criteria (liberal, conservative, and most conservative) for judgement of the validity of the Threshold Hypothesis. Regardless of the differing threshold point, the results showed significant threshold effect. Yet, multiple studies proved otherwise (Kim, 2005; Sligh et al., 2005).
Literatures refuting the Threshold Hypothesis showed no significant differences in the correlation of intelligence and creativity between average and high IQ groups (Kim, 2005; Sligh et al., 2005). Both gc and gf were measured and significant correlation to creativity was observed in both average and low IQ for the test on gc; furthermore, there was higher correlation to creativity in the higher IQ range for test of gf (Sligh et al., 2005). The findings seem relevant to the notion that gc influences creativity and in turn affects gf – people high in gc utilizes their acquired knowledge to solve problems, fostering creativity; these people frequently initiate creative thinking thereby increasing gf (Sligh et al., 2005). The influence of gc on creativity is replicated in Cho et al.’s (2010) study. A meta-analytical finding by Kim (2005), however, found only modest correlation between intelligence and creativity. While the study refutes the Threshold Hypothesis, it contradicts Sligh et al.’s (2005) notion that intelligence and creativity has a mutual affect; it also does not support multiple other studies that explain the relationship between intelligence and creativity (Cho et al., 2010; Nusbaum & Silvia, 2010; Benedek, Jauk, Sommer, Arendasy, & Neubauer, 2014). It is worthwhile to note that Kim’s (2005) study is not without flaw – the study is only a summary of results and not a new analysis (Karwowski & Gralewski, 2013); and a potential underlying methodological problem is that the average uniqueness score of the sample drops as the sample size increases because it is more difficult to identify unique responses (Nusbaum & Silvia, 2011). Put together, the results suggest possible alternative explanations to the relationship between intelligence and creativity besides the Threshold Hypothesis.
One alternative hypothesis is that intelligence and creativity is linked by executive functions – updating, shifting and inhibition: Updating refers to the manipulation of information in the working memory to match the immediate task. Shifting refers to switching between different tasks. Inhibition refers to holding irrelevant but prevailing impulses back (Benedek et al., 2014). The study found updating as the central executive function interplaying intelligence (measured as gf) and creativity; while inhibition has a slight correlation to creativity. Both executive functions can work together to facilitate creative thinking (Benedek et al., 2014); and since updating is a central mechanism in intelligence and creativity, it can be deduced that the two constructs are highly related. The theory of interplaying executive functions is supported by Nusbaum and Silvia (2010) whom found that the executive function (termed as executive process/ability in the literature) of switching (synonymous to shifting in Benedek et al., 2014) and inhibition are predictive of the intelligence-creativity relationship. Indeed the results show that the intelligence-creativity relationship can be explained by executive functions, but the discrepancy on the specific executive function suggest that more research is required to arrive at more conclusive results.
Another theory disagrees with Benedek et al. (2014), Nusbaum and Silvia (2010) that intelligence and creativity are more similar than different constructs. The theory suggests that intelligence and creativity are regarded as two different mental operations – convergent and divergent thinking respectively: convergent thinking results in one solution whereas divergent thinking involves giving a diversity of answers (Cho et al., 2010). The study posited that the mental operations of intelligence differs from creativity because the g score corresponded to different components of the creativity test rather than the common factors of fluency and originality; also, gc is essential to foster creativity (Cho et al., 2010). Perversely, Nusbaum and Silvia (2010) found that the mental process of creativity is more similar to that of intelligence than current theories on creativity suggest. The inconsistency of results may once again be explained by the differing measures of intelligence and creativity (Kim, 2005; Nusbaum & Silvia, 2010).
In conclusion, the Threshold Hypothesis seeks to explain the relationship between intelligence and creativity. There has been no consensus or a conclusive decision on the hypothesis due to inconsistency in results. Studies supporting the hypothesis found a threshold effect albeit at varying points whereas contradictory studies either found low correlations between intelligence and creativity or no significant threshold effect between the average and high IQ groups. Possible alternative theories that explain the intelligence-creativity relationship include common executive functions in both mental constructs; and differences in mental processes. In comparison, the current results suggest that intelligence and creativity are more similar than different, however, they are not the same. While the difference in mental operations ostensibly sets forth certain differences in the two constructs, the studies on common executive functions establish a more convincing theory that intelligence and creativity are highly related mental constructs. At present, it seems that the similarities outweigh the differences between the two constructs. The current research requires further studies that include factors such as personality traits, motivation and other factors of intelligence and creativity (Benedek et al., 2014; Karwowski & Gralewski, 2013; Nusbaum & Silvia, 2011; Sligh et al., 2005; Kim, 2005) to be incorporated in order to reach a more conclusive decision.