The fact that the data is taken from speed dating loads the results, as speed dating attracts a certain kind of demographic. Not only that, but the nature of the time constraints in that atmosphere provide inadequate time to dig deeper then a superficial level. It should not be taken to assume that this is representative of a culture as a whole, and especially not as a global or universal truth. This is not to say the data is invalid, just that it shouldn't be read into too deeply, as this is not a deep enough study to make grand conclusions.