There are two kinds of farts – the ones that come from your family and the ones that come out of everyone else – and one smells way worse than the other. According to science, there’s actually a really interesting reason why (or a few reasons, as it turns out).
First, you and your immediate family tend to have an identical or similar diet, which means your microbiomes are also similar. Farts become a joke, since they don’t make you want to clear out of the room upon impact.
“Food is a major driver of the microbiome because families eat together and have many shared eating patterns, therefore this increases microbes shared,” explained Dr. Terry Wahls, a doctor who specializes in gut health.
Touching and cohabitation can also effect microbiomes, which is why young children are likely to share gut bacteria, and mothers especially pass those microbes on to babies during childbirth. Unfortunately, that also goes for the bad stuff – DNA also plays a role, so if you have smelly farts, chances are that your kids will, too.
“Your ability to produce significant quantities of methane – one of the multiple components in intestinal gas – is based on genetics. The offspring of two methane producers have a 95 percent of being a methane producer,” said Tracy Lockwood in Men’s Health.
There’s an evolutionary reason for farts, too – bad smells signal threats to humans, but when we encounter the same bad smells over and over again without being harmed, we notice them less and less.
“In nature, survival depends on your ability to detect other smells, so you tend to ignore your own,” Inner Mammal Institute founder Loretta Breuning reiterated to Men’s Health.
So, while it’s okay to make jokes about your smells at home, you’ll probably still want to teach your kids to go into another room if guests are over (and to find a restroom – or someone to blame it on – in public).