A study has found that the ‘hunter-gather instincts’ that helped our ancestors avoid starvation by seeking out high-calorie foods make us better at recalling where junk food is.
Researchers from the Netherlands found that test subjects could more accurately recall the location of high-calorie foods than their lower-calorie counterparts.
This rule applied regardless of whether the experimental participants liked the food in question, or how familiar they were with the item.
The findings indicate that our spatial memory — which allows us to remember the relative locations of objects — has evolved to prioritise high-calorie foods.
Rachelle de Vries of Wageningen University and colleagues measured food location memory by asking 512 participants to follow a fixed route around a room containing either eight food samples, or eight food-scented cotton pads.
When participants reached a sample, they either tasted the food or smelled the cotton pad and rated how much they liked it.
Both samples included apples, crisps, cucumbers and chocolate brownies.
Participants were then asked to indicate the location of each food or food odour sample on a map of the room.
The study found that those presented with food samples were 27 per cent more accurate at mapping high- than low-calorie foods to the correct location, and those presented with food odour samples were 28 per cent more accurate at the same.
The researchers noted that the subjects’ memories were not affected by whether foods were sweet or savoury or how much participants liked each sample.
They found that the overall mapping of foods was almost two-and-a-half times more accurate when participants were presented with food rather than the cotton pads.
‘We found that individuals incidentally learned and more accurately recalled locations of high-calorie foods — regardless of explicit hedonic valuations or personal familiarity with foods,’ the researchers wrote.
‘In addition, the high-calorie bias in human spatial memory already became evident within a limited sensory environment, where solely odour information was available.’
‘These results suggest that human minds continue to house a cognitive system optimised for energy-efficient foraging within erratic food habitats of the past — and highlight the often-underestimated capabilities of the human olfactory sense.’
The full findings of the study were published in the journal Scientific Reports.