We humans are unimpressive candidates for planetary domination: we’re weak, defenceless, and can’t even outrun other top predators. Instead, the argument goes, we gained an unprecedented degree of evolutionary success through brain power alone. So why aren’t creative and learning abilities – supposed hallmarks of human intelligence – more common in nature? (Not to mention the large brain accompanying them.) If intelligence were really a foolproof route to evolutionary success, we might expect big brains to be in the majority. However, this isn’t the case. Although some animals are capable of feats of complex learning and memory, many others have managed perfectly well over millennia with tiny brains.

At this point we might ask if intelligence is really that useful. For some species, the answer can be ‘not very’. Depending on the context, the evolutionary cost of intelligence may outweigh its benefits. Several years ago, Tadeusz Kawecki’s research group created populations of fast-learning fruit flies. Fruit flies are one of the best organisms in which to study evolutionary processes: they breed prolifically and, most importantly, have a short generation time, which allows human researchers to track changes in a population over a practical time frame. They taught groups of flies to associate a particular scent with unpleasant stimuli and only bred those that learned to avoid the scent. The super-smart descendants of these flies learned faster, but their improved ability to learn came at a cost: they did not succeed against a line of normal flies when competing for limited food, and died more quickly when deprived of water. In some cases, the researchers even found that greater learning ability was associated with decreased lifespan. They also found that another line of flies, selected for longevity, were 40 per cent worse at learning in early life than normal flies.

These drawbacks of higher intelligence may reflect the investment of energy in maintaining more neural connections and, perhaps, a larger brain. Certainly it seems that while greater intelligence may enhance survival in some situations, it can be downright detrimental in others (at least in laboratory populations). Natural selection would only favour increased intelligence in populations where its total benefits are greater than its cost. If such environments are comparatively rare, perhaps this is why most animals have remained with comparatively small brains over time.

Such results force us to rethink our perspective on creativity, learning, and all the mental processes supposedly ‘essential’ for our evolutionary success. It may be better for us to describe intelligence as one survival strategy among many. Even though it may allow an animal to discover a better food source or alternative ways of attracting mates, creativity can still lead to time being wasted on experiments that don’t work (as every science PhD student will attest).

It’s also true that creativity and innovation are most often used to solve problems when things are going badly, at least for human endeavours. However, this also seems to be true across the natural world, and animals that would otherwise be evolutionary losers tend to innovate the most. For example, if you were a low-ranking individual in a group and had less access to food, searching for novel food sources might be the only way for you to survive during a drought. Perhaps the evolutionary story of human intelligence isn’t actually one of brilliant individuals outstripping others, but of losers struggling to survive.