Science is often an egoistic pursuit. Something about developing a theory seems to inject an arrogance into the method. This can lead to a relentless pursuit of that theory in the face of mounting evidence to the contrary. And perhaps it's not a bad thing. The scientific method holds at its core this combative ideal: develop a hypothesis and then try to break it. It has however led to many unfortunate ideas spreading into the popular consciousness.
Psychology is a fabulous case study for this. Consider the stranglehold behaviourism had on psychology for almost 40 years: only looking at behaviour and ignoring the fact that we also think. It wasn't until the 1960's with Aaron Beck's research into depression that the 'cognitive' part of cognitive behavioural therapy was even considered. Or take Freud's less savoury propositions, like his 'Oedipal desires', and the questionable notion of 'recovered memories' of sexual abuse, the atrocious negative impacts of which still [linger in justice systems today].
A principle reason for this kind of error appears to be that theory building, particularly in the earlier stages of a given discipline, is predominantly a philosophical exercise. Philosophy can be conducted in many ways, but one method has dominated throughout history: conceptual analysis. Here, one tries to answer questions by posing a hypothesis against hypothetical counter-examples. Without delving too deep into the pros and cons of the method, it's true to say that conceptual analysis frequently fails to engage with developments in the sciences.
Psychology again forms a useful case study, historically neglecting the implications of evolution. Professor Martin Daly of McMaster University put it very succinctly:
The reason why psychologists have wandered down so many garden paths is not that their subject is resistant to the scientific method, but that it has been inadequately informed by selectionist thought. Had Freud better understood Darwin, for example, the world would have been spared such fantastic dead-end notions as Oedipal desires and death instincts.
What is evolutionary theory?
The evolutionary approach to psychology is only one of many approaches to the study of the mind, and presents with some of its own issues But it has been fairly formative in narrowing the range of theories from the apparently plausible, to the actually plausible.
As explained to us by Charles Darwin and his now oft-forgotten peer Alfred Russell Wallace, the theory of evolution is based on principles of natural selection. Over time, the process of living filters, or 'selects' those who:
- live longer (and thus)
- reproduce successfully.
As Clark L. Hull put it:
Since the publication by Charles Darwin on the Origin of Species it has been necessary to think of organisms against a background of organic evolution and to consider both organismic structure and function in terms of survival.
Evolutionary theory then, provides us a tool to refine our ideas about how the mind works, or to figure out theories actually hold water. In the 1960's, Dutch scientist Nikolaas Tinbergen developed something of a checklist to this effect. He points out that any explanation of behaviour must consider four questions:
- the mechanism (the what) - what causes or triggers the behaviour?
- the ontogenic (the how) - how does this thing develop over the lifespan? How does it translate from DNA to behaviour? Is it learned, or innate?
- the phylogenetic (the when) - when did this behaviour begin in the species? Is it phylogentically recent (e.g. a feature of mammals) or distant (e.g. a feature of even invertebrates
- and all of the above are clues to the functional (the why) - what are the ultimate reasons for this behaviour's existence? What purpose does it serve?
An example: personality
To illustrate, we can look to personality in humans. Trying to categorise the various faces of human personality has been a recurring project of psychology. From the 'melancholic' and 'phlegmatic' of the ancient Greeks, to the very dominant big five model today. Yet, the sheer number of personality types, and personality traits, indicates that this is a field that could benefit from some narrowing. And indeed, applying Tinbergen's framework proves useful here. In the big five model, mentioned earlier, there is a personality trait called 'extraversion': the origin of the idea of extraverts and introverts. If you're higher in extraversion then you're more energetic and outgoing. If you're lower, then you're more reserved and prefer to be around people less. A very intuitive dichotomy, hence it's popularity outside of the research setting. But when we look to Tinbergen's question, it appears that actually extraversion is less of this smooth continuum, and more of a landscape of traits that in different combinations result in different peaks and valleys of extraversion. Zuckerman's 'sensation-seeking' is one of the better studied:
- the mechanism - it would appear that higher levels of testosterone results in people engaging in more risky and sensationally intense activities (although that may not be the whole story)
- the ontogenic - family dynamics and community culture can encourage or discourage these behaviours, permitting (or not) the spread of this trait into the population
- the phylogenetic - the neurotransmitter dopamine, and the systems that use it, has been found to vary with sensation-seeking-type behaviour across many different animals
- the function - extraversion more broadly has been tied to success in mating, but sensation seeking in particular comes with a fairly obvious evolutionary cost-benefit tradeoff: more risk of harm, but the possibilities of higher rewards in the exploration of new things
Thus, sensation-seeking appears to be a sensible personality trait, evolutionarily speaking. Indeed, it comprises many of the attributes we would characterise someone who is high in extraversion. In this case, it helps us draw a line between sensation-seeking-type impulsivity or risk-taking and other aspects of extraversion like the social component. It also highlights the danger of stopping with the intuitive explanation: that extraversion is a continuum.
Tinbergen's questions, and evolutionary theory more broadly, are just one example of a method to refine our thinking. The larger point concerns the tendency to sail a theory, against the wind, until it sinks beneath us rather than adjusting the sails. Examples of both litter the academic ecosystem, but the former is the approach that tends to leak into public domain. It's to our detriment.
In 1934, John Henry Wigmore put forward his hugely influential Treatise on Evidence. In it, he warns that women and children are likely to accuse men of 'good character' of sexual abuse and should thus be subject to examination by a psychiatrist. Freud's work on sexual abuse popularised the idea that one could 'recover' memories of sexual abuse during therapy. Today we know this idea to be largely more harmful than helpful. Yet the notion flourishes every 30 years or so sparking a surge of accusations that later turn out to be more commonly the product of an imaginative therapist's leading questions of a vulnerable patient. This is not to say that sexual abuse can't be repressed, but that Freud's methodology was deeply flawed and his influence outsized. Wigmore's thinking was influenced in no small part by one of these blossoms of misplaced enthusiasm. In the light of many distressing stories that are surfacing in this #metoo moment, and the ongoing exposure of huge rings of sexual exploitation perpetrated by powerful individuals largely unchecked by our social norms and our justice systems, one wonders how different the last 70 years would have been if Freud and his fans would have spent more time adjusting their sails.