Has evolution wired you to pursue happiness? Some researchers think so.

The granddaddy of positive psychology Martin Seligman draws on evolutionary theory – or at least its bastard offspring, evolutionary psychology – to explain why we go to such lengths in search of happiness.

In his book Authentic Happiness, Seligman argues happiness and other positive emotions “have a grand purpose in evolution”:

They broaden our abiding intellectual, physical and social resources, building up reserves we can draw upon when a threat or opportunity presents itself.

Just as fear provokes a fight-or-flight response when we’re faced with danger, Seligman claims positive emotions alert us to win–win situations.

Similarly, in Happiness: The Science Behind Your Smile, Daniel Nettle argues happiness is indirectly linked to evolutionary survival. The promise of happiness, he reasons, is a mirage that motivates us to get out of bed in the morning to do chores we don’t like. It’s why we try to chat up potential mates who are clearly out of our league.

We are designed not for happiness or unhappiness … but to strive for the goals that evolution has built into us. Happiness is a handmaiden to evolution’s purposes here, functioning not so much as an actual reward but as an imaginary goal that gives us direction and purpose.

It all sounds rigorously scientific, but is it?

The use of the term “evolution” makes evolutionary psychology sound as though it’s at home in the natural sciences, just next door to biology. But there are some problems when you apply evolution to psychological states such as happiness. Not the least of these is the problem of reliable evidence.

Theories of biological evolution can be backed up with objective evidence such as fossil records, DNA analysis and climate data. Evidence for the role of psychological states in natural selection is harder to come by.

This is because emotions don’t leave specific physical traces. You can’t, for example, carbon-date happiness. Nor can you find fossils of depression.

Of course, you can find physical traces of early human societies. But it’s just speculation — interesting speculation perhaps, but speculation nonetheless — as to what was going through the heads of the people who lived in these societies. And it’s another thing entirely to say with any certainty what they felt, what motivations drove them and what meanings they attached to their behaviours.

To get an idea of how heavily the odds are stacked against evolutionary psychologists, consider how often mistakes appear in the daily press. Even better, if you or someone you know has ever been quizzed by a journalist on a particular issue, think about whether you or your friend felt your views had been accurately reported.

Chances are, you felt your views or feelings hadn’t been faithfully reported in their full complexity. Perhaps they were taken out of context or the nuance was missed. Or you may have felt completely misrepresented.

It may have been that the journalist was incompetent or unprofessional. But it’s also more than likely that representing the motivations, views and ideas of human beings is a mind-bogglingly difficult business, even when you’re having a conversation with the person.

If journalists can make elementary mistakes about people who are right in front of them and who, presumably, are able to talk about motivations for behaving as they do, then the chances of an evolutionary psychologist getting things right about people and groups who are long dead aren’t promising.

Evolutionary psychologists respond to this sort of objection by saying their accounts rest only on the most fundamental and enduring features of human societies. These include the fact human beings live in groups and need basic and often scarce resources to survive, such as food, water and warmth. And such groups face competition for these resources from other groups and predators.

Given these elements are common to all human societies, the argument goes that we can have some confidence about what evolutionary psychologists tell us about the contributions that mental states have made to our survival.

But it is possible to come up with a plausible explanation for what role happiness – or any psychological state for that matter – might have played in our survival, and then be completely wrong about it.

And not only would it be possible to be wrong, it would also be impossible to tell if you were right or wrong since there’s no way of testing it.

This is perhaps the most damaging fact about evolutionary psychology’s scientific credentials: science rests on the capacity to test a hypothesis. If you can’t devise a test to check whether a hypothesis is right or wrong, then whatever you’re doing, it isn’t science.

This points to a larger problem with invoking evolution to explain this or that feature of human experience. Evolution’s success has encouraged people to extend it to a whole series of fields where it does not really belong.

Charles Darwin himself saw the potential problem of using evolution as a theory of everything. As Mary Midgley notes in The Myths We Live By, for Darwin:

…the concept of natural selection was strictly and solely a biological one and even in biology he steadily rejected the claim that it was a universal explanation.

Darwin didn’t even think that natural selection was sufficient to explain every biological change. Midgley goes on to quote his biography in which he reiterates the point:

As my conclusions have lately been much misrepresented, and it has been stated that I attribute the modification of species exclusively to natural selection, I may be permitted to remark that in the first edition of this work, and subsequently, I placed in a most conspicuous position — namely at the close of the Introduction – the following words: “I am convinced that natural selection has been the main, but not the exclusive, means of modification.” This has been of no avail. Great is the power of steady misrepresentation.

As such, it seems wise to drop the word “evolution” — along with the connotations of hard science that accompany it — and refer to evolutionary psychology as “speculative psychology”.

Likewise, any attempt to dress happiness research in the garb of the natural sciences ought to be taken with a very large grain of salt.