People often act strangely when they fly. It seems there's something about being herded up in a group and told to sit in an allocated seat for the foreseeable future that makes people forgot the social norms we typically live by. Perhaps it's the loss of control that makes passengers grasp for whatever kind of dominance they can get. Whether it's becoming possessive about overhead bin space or being precious over armrests, many travellers act differently in the air than they would on the ground. This can make the unwritten rules of air travel hard to comprehend. A recent survey by YouGov is on hand to help with that by revealing what fellow passengers think are the most acceptable and unacceptable behaviours on an aircraft. First up is one of the long-running debates when it comes to flying – whether passengers should recline their seats or not. According to the YouGov survey, which quizzed 1,219 adults in the United States, 69 per cent of respondents agreed that it's fine to recline. Generation X – people born between 1965 and 1981 – were the most relaxed about seat recline with 36 per cent of those surveyed happy for travellers to do so. The youngest travellers, Gen Z – those born after 2000 – were the least in favour of reclining, with only 23 per cent of respondents happy for people to lean back. When it comes to making conversation, it seems a little goes a long way. Most respondents – 35 per cent – said that "exchanging pleasantries" was best when it comes to in-flight conversation. This was followed by 32 per cent of people who answered that it was OK to converse a little. Only five per cent of people preferred a lot of conversation and 15 per cent of people opted to not talk at all to fellow travellers. The most unacceptable thing you can do on an aircraft is bring pungent food on board with you. More than 69 per of all respondents across all generations said that taking smelly food on an aircraft was unacceptable behaviour. Baby boomers were the most offended by this, with 56 per cent finding it entirely unacceptable. Millennials found it the least offensive, but still over half of those born between 1982 and 1999 said it was a no-go. So it might be wise to skip the preflight KFC stop. Taking your shoes off on an aircraft seems to be a controversial topic. According to the survey, 34 per cent of travellers deemed it completely unacceptable while 24 per cent were fine with travellers slipping off their shoes. Next time you fly, you might want to check who you're sitting next to before you untie your laces – Gen Z and millennials are the most relaxed about the practice while older travellers frown upon it. The unspoken rule of thumb that travellers in the middle seat should get both internal armrests is not universal. When asked whether the middle passengers in a row of three aircraft seats should have more, less or equal claim to those armrests than passengers in window or aisle seats, most US travellers surveyed said that all passengers should have equal claim. Women felt particularly strongly about this, with 63 per cent voting for equal distribution. Gen Z are the most generous when it comes to sparing a thought for middle-seated flyers, with 34 per cent of younger travellers believing that person should get more armrest space. Despite announcements at the start of every flight telling passengers to turn their phones off or to switch them to flight mode, some travellers continue to defy the rules. Five per cent of US travellers do not turn their phones off on a plane, with Gen Z travellers being the most guilty. The Silent Generation – travellers born between 1928 and 1945 – prefer to switch off phones completely, most other travellers turn on flight mode in the air. There's been a rise in the number of emotional support animals being brought on to flights in recent years but not all furry friends rank equal in the eyes of travellers. Dogs are the most accepted type of support animal with 66 per cent of Americans ranking them as acceptable emotional support animals. Cats were ranked in second place, finding favour with just over half of all travellers questioned. Other animals are not so welcome in the air, with snakes being the most unacceptable according to 66 per cent of travellers. Peacocks, hamsters and emotional-support squirrels were also frowned upon. There were no questions about emotional-support horses but several airlines allow the animals on flights. A woman made headlines earlier this year when she flew American Airlines from Chicago with her emotional support miniature horse Flirty beside her.