<p>My understanding from a biological perspective is that the maturity gap between boys and girls is really referring to something that happens around the early teens, and that by ~17 boys have caught up. (In other words, the "maturity gap" is not a good reason to tolerate a nineteen year old girl dating a thirty year old man.)</p>
<p>Of course, many students take the SATs at 16 or whatnot, so I suppose that still makes sense.</p>