Washington, Sept 26 : Modern humans still retain caveman’s survival instincts at spotting predators and prey, despite living in the comforts of modern homes in urban localities, according to a new study published online in this week’s issue of the Proceedings of the National Academy of Sciences (PNAS).

The study reveals that humans today are hard-wired to pay attention to other people and animals much more than non-living things, even if inanimate objects are the primary hazards for modern, urbanized folks.

The scientists say the finding supports the idea that natural selection moulded mechanisms into our ancestors' brains that were specialized for paying attention to humans and other animals, and these adaptive traits were then passed on to us.

“We're assuming that natural selection takes a long time to build anything anew and that's why this is left over from our past,” said study team member Leda Cosmides, an evolutionary psychologist at the University of California, Santa Barbara (UCSB).

In the study, groups of undergraduate students from UCSB were asked to watch images displayed on computer monitors.

The flashing images alternated between pairs of various outdoor scenes, with the first image showing one scene and the next an alternate version of that scene with one change. Participants indicated each time whether they detected a change.

The photographs included animate categories, such as people and other animals, as well as inanimate ones, such as plants, artefacts that could be manipulated (stapler or wheelbarrow) and fixed artefacts, such as landmarks (windmill or house).

The researchers found, that overall, the subjects were faster and more accurate at detecting changes involving all animals compared with inanimate objects.

They correctly detected nearly 90 percent of the changes to “living” targets compared with 66 percent for inanimate objects.

In particular, the students spotted changes in elephant and human scenes 100 percent of the time, while they had a success rate of just over 75 percent for photos showing a silo and 67 percent for those with a coffee mug.

Elsewhere, the subjects were slower and less successful at detecting changes to vehicles than to animals.

Study team member Joshua New of Yale University's Perception and Cognition Lab, said, while the environment has changed a lot since the Stone Age, human instinct has remained the same.

“Having this pop-out attentional bias for animals is sort of a vestigial behaviour.
People develop phobias for spiders and snakes and things that were ancestral threats. It's very infrequent to have somebody afraid of cars or electrical outlets. Those statistically pose much more of a threat to us than a tiger,” said New.

“That makes it an interesting test case as to why do tigers still capture attention,” LiveScience quoted New, as saying. (With inputs from ANI)