I've heard this thrown around and while it may hold merit with a compliance test, I think taken at face value just means you're missing out. Its perfectly fine to buy a girl a drink, but only if she doesn't ask/expect it.
This is because of a powerfull social dynamic known as the rule of reciprocation.
Reciprocation can be observed in the sub-conscious and is often exploited widely these days in the world of PR/Marketing where by the target receives a "free gift" in the effort to elicit a return favour (i.e. buying the product/service or at the very least subjecting oneself to the prospect of engaging with a brand or company). It is said to have originated back to primitive social interaction by way of trading of goods or services to the benefit of personal survival and building community (you scratch my back, I scratch yours). This was way before economics and occurred where during a transaction of 2 parties, one would have to relinquish time/service/product first in order to break any stalemate. This lead to a powerful urge to reciprocate, since this was a sustainable benefit of both individuals and therefore society. The interesting part about this is the reciprocation is generally larger than the initial offering. If you are interested in this topic, it is one of many covered (with scientific study references) in Influence: The psychology of persuasion by Robert B. Cialdini
So, if you're buying a girl a drink out of "good nature" she WILL feel obligated to return the favour in some form. Though this will be reflective on whatever value her mind has on alcohol (i.e. students value it more than mature professionals).
This is because of a powerfull social dynamic known as the rule of reciprocation.
Reciprocation can be observed in the sub-conscious and is often exploited widely these days in the world of PR/Marketing where by the target receives a "free gift" in the effort to elicit a return favour (i.e. buying the product/service or at the very least subjecting oneself to the prospect of engaging with a brand or company). It is said to have originated back to primitive social interaction by way of trading of goods or services to the benefit of personal survival and building community (you scratch my back, I scratch yours). This was way before economics and occurred where during a transaction of 2 parties, one would have to relinquish time/service/product first in order to break any stalemate. This lead to a powerful urge to reciprocate, since this was a sustainable benefit of both individuals and therefore society. The interesting part about this is the reciprocation is generally larger than the initial offering. If you are interested in this topic, it is one of many covered (with scientific study references) in Influence: The psychology of persuasion by Robert B. Cialdini
So, if you're buying a girl a drink out of "good nature" she WILL feel obligated to return the favour in some form. Though this will be reflective on whatever value her mind has on alcohol (i.e. students value it more than mature professionals).