In many cultures, a kiss is as familiar as a handshake and wouldn't raise any eyebrows in the street. But in some parts of the world, the action is considered awkward or even unpleasant - which is something to bear in mind if you get caught up in a holiday romance over the summer.

A new study in the American Anthropologist Journal looked at 168 different cultures across a wide range of geographical locations to track current attitudes to smooching. In only 46 percent of these cultures is kissing used as a sign of romantic affection, so relationships in more than half of these areas are kissing-free (kissing in this case defined as deliberate and prolonged contact with the lips).

The study found plenty of variation across the globe: the habit of kissing was observed in seven out of 10 cultures in Europe, 18 out of 33 cultures in North America, four out of 33 cultures in South America, and 10 out of 10 of the cultures studied in the Middle East (obviously the place to be if you enjoy locking lips with your partner).

The researchers say that there's little evidence for 'romantic-sexual' kissing in hunter-gatherer or forager communities, and the suggestion is it's not something our ancestors particularly went in for. According to the report, it's "Western ethnocentrism" that's "driving the common misconception that romantic-sexual kissing is [near] universal".

So why do we do it? The theories include the idea that it was originally a way of assessing a potential mate's health and compatibility, or that it's a natural way of spreading germs and thus increasing resistance to them. Class could be a factor too: based on the findings, it's possible that "the emergence of the romantic-sexual kiss may coincide with other factors, such as oral hygiene or the rise of elite social classes that value self-control of affect and emotional displays", say the researchers.

The academics, including William Jankowiak and Shelly Volsche from the University of Nevada and Justin Garcia of Indiana University, also looked back at kissing through the ages, and the way that kissing was considered 'gross' by some communities when they were first exposed to it. Anthropologists are split on whether the action is instinctive or an evolution of the mother-to-child feeding action.

"The romantic–sexual kiss may be a seemingly pleasurable part of sexual repertoires that vary across place and time but anchors on the truly universal human capacity for romantic love," concludes the report - just don't assume that it's universal.