It's a real science - just one where we would like more data.

<snark> Ah, yes. And that is why, every summer, when teaching duties are completed, the practitioners of evolutionary psych and their graduate students head out into the field to collect more data! </snark>

And Neanderthal resurrection will tell us next to nothing, since we still will have no idea what selective pressures our ancestors faced or what pressures Neanderthal ancestors faced. To say nothing of the difficulty in assessing the differences between Neanderthal psychology and H. sapiens psychology. And even if this weren't a problem, we would still have only two data points to work with.