Ladies, listen up! I’ve discovered the secret — the reason why men everywhere are unintelligible assholes. It’s because, apparently, “dickhead,” in guy talk, means “friend” and “hey buttwipe!” means “I missed you.” I know, shocking.

These and other astounding revelations are brought to you by Michael Van Osch in the one-man show “Defending the Caveman,” now at Long Wharf Theatre. Written by comedian Rob Becker and performed on circuit for several years, the performance is touted by Long Wharf as “a hilariously insightful show about the ways men and women relate” — a description that is clearly wishful thinking. Set on a spare yet iconic stage decorated with (what else?) cave paintings of a man hunting a bison and a “Flintstones”-inspired recliner-and-TV set, this show provides only one major insight: People are still willing to pay for this.

I tried hard to laugh, really. And obviously, there was something funny — much of the septuagenarian-heavy audience chuckled and guffawed at all of Van Osch’s significant pauses. Maybe I’m just 20 years early to the party (Van Osch was born in 1966, so he’s exactly twice my age). Maybe this is one of those times where your wise and hallowed elders pat your arm patronizingly and say, “Don’t worry, you’ll appreciate it when you’re older.”

Somehow, I doubt it. The humor runs along the lines of “me caveman, you cavewoman” — the old, tired “evolutionary biology” pony that was ridden to death by the time Harry met Sally. You know, the highly scientific observation that modern man is the way he is because he used to be a “hunter” (see the large cave painting of a man hunting a bison), so he can only focus on one thing at a time and can’t form coherent sentences. And that women were “gatherers,” which is why they are smart and can multitask and like to shop. It’s an attractive, if simplistic, proposition.

And Becker clearly intends to strip-mine it for comedic gold. Ignoring some bizarre hallucinogenic moments — Van Osch recounts an experience where he “sees” a caveman who shows him the light of gender differences (then the caveman steals his hockey trophy before disappearing back into ether) — the male-female divide is ruthlessly exploited for predictable LOLz. Men don’t talk as much as women because they had to be quiet for the hunt. Women needed to be sensitive to pattern and color to find ripe fruit — that’s why they like shopping. Ha ha ha. There is literally nothing that you haven’t already seen in a sitcom or romantic comedy, and the show only hits its mark when the human element — Van Osch — manages to strike just the right note.

The funniest parts are when Van Osch pretends to be a man acting like a woman, and role-plays the resulting dude weirdout . Even these are cheap shots: seeing a guy get uncomfortable after his buddy calls him up just to “talk about his feelings” is not exactly cutting edge. Yet these scant moments of the 90-minute performance showcase Van Osch’s everyman charm, a welcome respite from the pedantic wink-wink-nudge-nudgery of the rest of the show.

In an unsettling way, “Defending the Caveman” ends up being one long, tortured apology-cum-soliloquy begging women’s forgiveness for men being “assholes,” but you shouldn’t blame the poor blokes, that’s just the way they are. It feels feeble, not to mention dated (back in 1995, the New York Times called it “middle-class mall humor delivered in the jerky rhythms of television’s stand-up comics” when it reviewed Becker’s original performance). Why does the caveman need defense? Who’s attacking him in any serious way these days?

It makes you wonder. Do the jokes fall flat because we’ve heard them all before (over and over and over)? Or is it because our generation is increasingly breaking out of Becker’s gender roles, and are no longer the easy bullseyes he was aiming for?

Then again, it could just be a question of experience. Maybe in 20 years I will be ROTFLing at “Defending the Caveman”’s truisms, affectionately nudging my spouse when we recognize each other in his words.

Until then, dickhead, why don’t you go hunt me a bison?