He's using PSYCHOLOGICAL warfare.
We must reply in kind.
The Big Bang Theory Season 1, Episode 13
Trust me, Kripke will fall easy prey
to my PSYCHOLOGICAL warfare. Observe.
The Big Bang Theory Season 2, Episode 12
...you may be alone
because your PSYCHOLOGICAL state...
The Big Bang Theory Season 4, Episode 5
Yeah, she's right. For every Newton
who had a PSYCHOLOGICAL issue,
The Big Bang Theory Season 9, Episode 10
...and PSYCHOLOGICAL implications
on human society.
The Big Bang Theory Season 3, Episode 11