For the “take with a grain of [margarita] salt” file:
The Beeb says ‘Glass hold’ reveals personality.
If the study is accurate, you probably want to hang out with
This type of drinker could be a man or a woman. They tend to be sociable and convivial and “like a laugh”.
They take short swigs from bottled drinks so they don’t miss out on chipping in with the conversation.
The bottle is held loosely at its shoulder for ease. This type of person is always happy to extend their social circle. The best way to approach them therefore is to leap directly into light, good-humoured conversation and make them laugh.
However, it’s probably a good idea to stay away from the browbeater, whether the study is accurate or not.