Intelligence, Sapience and Learning, part 3 – Testing for intelligence

David Scott and Sandra Leaton Gray

This blog post is Part 3 of a series relating to our newly published book: Intelligence, Sapience and Learning: Concepts, Framings and Practices.

A number of claims about human intelligence are made by the neurobiological community. The first of these is that the brains of some people seem to be more efficient than those of other people. In addition, a claim is made that specific genes have been identified which generate cellular properties associated with intelligence. These cellular properties have been found to be more in abundance in people who have been shown to be more intelligent.

There are perhaps three ways that we can understand the relationship between genetic capacity and the influence of the environment in the life cycle. The first of these is a neurobiological account in which all the significant characteristics of a human being are derived from their inherited capacities, the unique DNA pattern that all of us have. What this means is that our intelligence, our dispositional character, our physical characteristics, our sexuality, our thought patterns, are inherited from our biological parents. This is a determinist, reductionist and physicalist view of the relationship between nature and nurture, or heritability and environmental influences.

An alternative view of these relations might be called epigenetic. Epigenetics is an account of how human behaviours and changes to the environment can affect the way heritability or individual genetic arrangements work. Genetic changes are irreversible, whereas epigenetic changes are potentially reversible. The reason for this is that epigenetic changes are only concerned with how a person’s body reads a DNA sequence, whereas an individual’s genetic make-up, with the exception of radical surgical transformations, persist over the lifetime of the individual. Epigenetics then is the study of how cells control genetic activity without changing the DNA sequence. The question still remains as to which aspects of the human condition are influenced by the epigenetic relationship between a person’s genetic make-up and those environments within which they position themselves. Examples of these non-genetic factors are sexuality, intelligent activity, volitions, utterances and ethical behaviours.

The third position that can be taken with regards to genetic heritability is a learning perspective, where learning is understood in epistemological terms as one of three sites of knowledge: the world and its contents, the mediating arena between the contents of the world and objects in the mind where learning takes place, and the contents of the mind that allow us to make judgements, perceive the world and reflect on what we have perceived. What this means is that most human traits, behaviours, actions, attributes, characteristics and properties are not genetic or epigenetic in orientation and substance. For example, there is no such thing as a sexuality gene – we are homosexual, heterosexual, bisexual, asexual, polysexual, pansexual or transexual or a combination of these and can move between them, even if with the greatest difficulty. Sexuality is a learnt and formative characteristic.

In our everyday life we use a notion of intelligence that differentiates some human actions, beliefs, attitudes, characteristics, from others, as signs of being more or less intelligent. Traces of this general and nationwide notion of intelligence can be found in Charles Spearman’s idea of general intelligence or g developed in the early part of the last century. Testing for it then and now has always been problematic. Regardless of this, various tests have been devised, such as the Wechsler Adult Intelligent Scale (WAIS). This test attempts to combine the results of multiple cognitive tests, for characteristics such as processing speed, language use and so forth, in one measurement, a General IQ score. Claims made for this notion are that it is a genetic trait; that it correlates with life outcomes even when measured at an early stage in life; that it has stable characteristics across time in people; and that its heritability is extensive.

It is widely recognised that measuring intelligence is controversial, as it can be culturally specific. In other words, how well you do on a test is related to how similar you are in background to the people setting the test. As most psychologists in the early part of the 20^th century were white and middle class, their tests were often based on ideas and situations that they would have found familiar in a US or Northern European context. This disadvantaged non-native speakers, those from a deprived educational background, or indeed those from outside the US or Europe. Although there have been attempts to remedy this, by making tests as culturally neutral as possible, it is still difficult, if not impossible, to get to the absolute core of what constitutes intelligence, even if intelligence is defined in a very narrow sense.