Does your personal ban on smoking go out the window as soon as you've had a drink?
Reaching for a cigarette after drinking alcohol is not an uncommon behaviour, but according to a new study, we don't just do it to be sociable.
Scientists at the University of Missouri believe we crave cigarettes when drinking alcohol because nicotine is a stimulant.
In theory, this means that nicotine can counteract the feeling of sleepiness we sometimes get when drinking alcohol.
The researchers gave rats fitted with sleep-recording devices alcohol and nicotine and monitored the way each substance affected the brain.
They found that nicotine stimulated the rats' basal forebrain - an area of the brain thought to be associated with reflexes, learning and attention span.
As a result, the researchers concluded: "One reason why people use nicotine, a stimulant, with alcohol is to enhance recreational/pleasurable sensations while suppressing alcohol's aversive effects such as sleepiness."
The study is published in the Journal of Neurochemistry.
It isn't the first piece of research to suggest our behaviours around nicotine and alcohol are linked.
A previous study suggested the more you drink, the more likely you are to light up as "both substances are addictive".
"Both alcohol and nicotine are addictive and stimulate the part of your brain that acts on rewards," Marina Picciotto, professor of psychiatry at Yale University, told Men's Health at the time. "Taking one is like priming the pump - and it makes you crave the other."