A recent research says that being afraid of creepy crawlies has a scientific reason
The behavioural immune system is thought to be prompted by brain chemicals, including serotonin. This chemical is also found in areas of the brain involved in the sensation of disgust.
Do creepy crawlies like spiders, cockroaches and rats make you flinch? That doesn’t necessarily make you a wimp — it could mean you’re less likely to become ill, reports dailymail.co.uk.
The reason we flinch is down to a mechanism called the behavioural immune system. It is stimulated by sensing unwelcome objects via sight, sound, touch and smell, and makes us react to threats so we avoid them before they come into contact with our bodies.
A safeguard
It’s a crude way to help protect us from ill health, but now a new study from British Columbia University (where the term ‘behavioural immune system’ was coined) says it’s not just health it affects — it can also provide unique insight into all kinds of behaviour, from our choice of partner to the way we vote.
The major benefit of the behavioural immune system is its simplicity. It runs in tandem with our infection-fighting immune system, a sophisticated network of cells, tissues and organs that fight off illness and disease and prompt healing.
But this conventional immune system has its drawbacks. The tactics it uses to attack threats, such as bringing on inflammation and fever, can be debilitating, at least in the short-term.
It also uses a lot of energy the body could better utilise on other jobs.
The behavioral immune system
In a study of 25 men, scientists at the University of Wisconsin recently found that fighting a mild respiratory tract infection increased energy needs by 14 per cent.
The behavioural immune system, on the other hand, requires very little calorie expenditure. It makes you feel repulsed when you smell that piece of rotten food in the fridge — there’s no need to expend the energy on sending immune cells to fight off the invading bacteria that would be present should you eat that food, as you just avoid it in the first place.
The behavioural immune system is thought to be prompted by brain chemicals, including serotonin. This mood-enhancing chemical is also found in areas of the brain involved in the sensation of disgust and is very active in the gut, too, where it is well-placed to trigger nausea in response to disgust.
Disgust is fundamental
Disgust is a fundamental part of human nature — it is the voice of our ancestors,” says Dr Val Curtis, a hygiene specialist at the London School of Hygiene and Tropical Medicine and the author of Don’t Look, Don’t Touch, The Science Behind Revulsion.
“Research suggests there is a universal set of things that disgust people. They include body wastes, body contents, sick or unhygienic people, dirty environments, certain foods — especially if unfamiliar or spoiled — and certain animals, such as rats and cockroaches.
“Disgust is why we don’t sit next to people who have visible signs of disease, such as rashes and open wounds. “And disgust is partly the reason why we develop manners. We learn that spitting, for example, evokes feelings of disgust in other people, so we don’t do it.”
Health indicator
It can also be a fascinating indicator of overall health. Research from the University of Trnava, Slovakia, involving 100 volunteers, found those who had the greatest disgust of parasites and bugs were in better health than the others. “These results support the idea that disgust and fear of disease-relevant objects are emotions that prevent contact with contagious objects,” say the researchers.
Meanwhile, a study from Glasgow University found women with greater disgust levels are more likely to marry a masculine-sounding, macho-looking man. Women who said they disliked bugs found deeper voices and masculine body traits more attractive.
( Source : www.dailymail.co.uk )
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