Diamond Jackson from Corpus Christi, Texas, asks Bill all about the evolutionary backstory behind infatuation. Why do we fall in “love” at first sight? The Science Guy presents the idea that we’re still physically conditioned to want to pass on our genetic material as quickly as possible. Thus, infatuation is a leftover facet of old caveman living when predators roamed everywhere, threatening your genetic line. So infatuation was (and continues to be) a tool for encouraging folks to get busy.

Diamond Jackson: Hi Bill. My name is Diamond Jackson. I attend Texas A&M Corpus Christi and you’ll be coming to visit us in October here. I’m so excited for that. My question for you is what is the evolutionary benefit of infatuation and is it more physical or is it more emotional? So if you can give me that information, I would be so excited.

Bill Nye: Diamond, yes. Diamond, that’s a fabulous question. What’s the value of infatuation? Well what’s the difference between infatuation and love at first sight? And there’s just fabulous studies that have been done. We humans agonize over the small decisions. What pencil sharpener should I get? Should I buy this pair of shoes at this price or that pair of shoes at that price? But when it comes to selecting a mate — these big decisions — apparently you make them like that. These big decisions you make very quickly. You pick up so much information very fast that you can use that to direct the rest of your life. So the thing about infatuation, as I understand it, is it can be replaced by another one. Like you’re infatuated with this guy or gal and then somebody else comes along and you get infatuated with her or him. But you probably would have had genetic success with the first one. There was something about him or her that was really appealing.

By genetic success, Diamond, we're talking about having kids and raising a family. Now you will meet a lot of people who are a result of infatuational — if I can coin that adjective — relationships, people that have love at first sight and they got married. You meet that all the time. Las Vegas has a whole industry based on people that meet each other and get married. And get divorced. But whatever happens, it’s also reasonable that infatuation is an artifact, it's left over. There’s no evolutionary reason to get rid of it, so it’s still there. Like you see somebody — you were in desperate times. On the savannah, we have lions and tigers and bears coming to kill us. There’s a drought. In order to pass your genes on you’ve got to get it done right now. And so you’re infatuated; you have love at first sight; you have kids right away. Then the lions and tigers and bears take you and your spouse out. You disappear, but the kid lives on because you got busy right away. This is very reasonable to me. And then as society became successful, developed ways to farm, agriculture, have successful cities, the infatuation thing wasn’t as useful. But there’s no reason to get rid of it. Enjoy the infatuation. Best wishes to you and congratulations to the guy or the gal.