What is Intelligence?

Approximate reading time: 5 minutes

Defining intelligence is a highly controversial process. The conceptualisation of intelligence varies widely across the world and is heavily influenced by cultural values (Sternberg & Grigorenko, 2004). Some cultures emphasise practical skills and the ability to adapt to the challenges of everyday life, and some place particular value on the ability to communicate and empathise with others. Collectivistic cultures value collective intelligence: the ability to contribute to group cohesion by working collaboratively and communicating effectively. Other cultures (e.g., Native Americans and people from Africa) particularly respect the elders in their community because they believe that wisdom comes from life experiences. Anglo-European/American cultures commonly emphasise cognitive abilities that are related to academic achievement, such as rapid information processing, memory, language skills, mathematical aptitude, and logical reasoning (Sternberg & Grigorenko, 2004). However, even Western psychologists disagree on a single definition of intelligence. In this chapter we will discuss how different psychologists conceptualise intelligence, but we will particularly emphasise how psychology has contributed to the oppression of large groups of people (especially people of colour), through the misuse and misinterpretation of intelligence tests.

There is a long history of unfounded prejudicial attitudes about the intelligence of people of colour. Africans were engaging in sophisticated practices, such as bronze casting, iron making, and pyramid building, long before the Europeans did. However, Europeans arriving in the continent of Africa assumed that Black and Brown people were uncivilized and had low levels of intelligence (Guthrie, 1998). These dehumanising views were used to justify a long history of colonisation and the enslavement of African people in Europe and the United States. Even after slavery was abolished, psychologists in the United States used questionable “scientific” evidence to perpetuate racist beliefs (Guthrie, 1998). As you will read in this chapter, their “science” was based on poorly designed studies and biased tests (Guthrie, 1998). Even today, modern intelligence tests and other cognitive aptitude tests (including the SAT) are frequently criticised as being culturally unfair, and their continued use excludes many people belonging to marginalised groups from multiple educational and career opportunities (Helms, 2012; Washington et al., 2016).

IQ tests have historically included items with numerous confounding variables. In other words, IQ tests measure a wide variety of other variables (such as socio-economic background, and urban versus rural upbringing) making it difficult to differentiate which behaviour is due to IQ and which is due to other factors. For example, intelligence is more strongly related than any other individual difference variable to successful educational, occupational, economic, and social outcomes. Scores on intelligence tests predict academic and military performance, as well as success in a wide variety of jobs (Ones, Viswesvaran, & Dilchert, 2005; Schmidt & Hunter, 1998). Intelligence is also negatively correlated with criminal behaviours — the average intelligence quotient (IQ) of delinquent adolescents is about seven points lower than that of other adolescents (Wilson & Herrnstein, 1985) — and positively correlated with health-related outcomes, including longevity (Gottfredson, 2004; Gottfredson & Deary, 2004). At least some of this latter relationship may be due to the fact that people who are more intelligent are better able to predict and avoid accidents and to understand and follow instructions from doctors or on drug labels.

The advantages of having a higher IQ increase as life settings become more complex. As we shift towards a more knowledge-based economy from a production-based economy, higher IQ will continue to predict better life outcomes such as financial well-being and life satisfaction. The correlation between IQ and job performance is higher in more mentally demanding occupations, such as physician or lawyer, than in less mentally demanding occupations, like clerk or newspaper delivery person (Salgado et al., 2003). Although some specific personality traits, talents, and physical abilities are important for success in some jobs, intelligence predicts performance across all types of jobs.

Our vast intelligence also allows us to have language, defined as a system of communication that uses symbols in a regular way to create meaning. Language gives us the ability to communicate our intelligence to others by talking, reading, and writing. According to psychologist Steven Pinker (1994), language is the jewel in the crown of cognition. Although other species have at least some abilities to communicate, none of them have language. In the last section of this chapter, we will consider the structure and development of language, as well as its vital importance to human beings.