When making a difficult decision we try to use our brains to rationally weigh up the options, but more often than not, we find ourselves simply ‘knowing’ the right thing to do.
Many people attribute this ‘gut feeling’ to something other than logic or reason - a strong internal sense that pushes you in a particular direction.
Although it might sound like an old wives’ tale, scientists have now found that this ‘gut instinct’ is as essential to our survival as our cerebral matter.
The team of researchers found that making basic life or death decisions based on ‘hunger memories’ (or that feeling of hanger - otherwise known as the anger we experience when we’re hungry) is almost as effective as intelligent solutions.
Lead researcher Dr Andrew Higginson, from the University of Exeter, said: “Many of us sometimes get hangry, when hunger makes us emotional and changes our behaviour.”
“But, hunger can act as a memory telling us there’s not been much food around, which it’s important to respond to in the wild.”
The premise at the heart of this study is that an animal’s body condition tells it how successful it has been in the past, and so can (and should) act as a useful guide to how it should behave in the future.
Based on that premise, the team used computer simulation models to predict people’s responses in different states, either using their brain or their gut during periods of hunger.
They found that they had similar levels of effectiveness in making decisions.
Co-author Professor John McNamara, from the University of Bristol, said: “The usefulness of such memory means that animals, including humans, may appear to be processing a great deal of information in the brain when in fact they are just following their gut.”
Such a simple form of physiological memory may have allowed many species to avoid evolving large brains, which require a lot of energy: “If it costs a lot of resources to be so clever, then natural selection will have found a cheaper way to make decisions,” said McNamara.
Humans and other animals may even have emotions partly because emotional “memory” is so useful for survival, say the scientists.
“By using their body condition as a cue, the animals in our model can still perform well when the environmental conditions change suddenly,” said Higginson.
The study, reported in the journal Proceedings of the Royal Society B, is said to have implications for conservation.