The Lounge is rated Safe For Work. If you're about to post something inappropriate for a shared office environment, then don't post it. No ads, no abuse, and no programming questions. Trolling, (political, climate, religious or whatever) will result in your account being removed.
Lacking direction is often just the removal of a compass point, so you could have something like "Winter lacking direction = winter - W(est) = inter" or "Guard lacking direction = sentry - S(outh) = entry".
Could also be a non-cardinal point like SE (South East), NE (North East) etc. or in some cases the full word (north/south/east/west).
Whenever you find yourself on the side of the majority, it is time to pause and reflect. - Mark Twain
In lacking direction means I, i.e. remove N(orth) from In.
This would make the puzzle: I in basic instincts acts like neanderthals.
Either add I to the synonym of instinct
Neanderthals being extinct; remove I from Basic Instincts itself or a synonym?
I come up with this version simply because the first 'In' seems redundant somehow. Simply Lacking direction would've been good enough to convey the point about compass directions.
I had thought of CAVEMAN as well, and the best I could come up with was Basic Instinct = CRAVE, Direction = R for right, so Basic Instinct Lacking Direction = (CRAVE - R) = CAVE. But I was stuck on how to get MAN.