It's a classic piece of idiot journalism worthy of a Full Liberman* if only it weren't so trivial and obvious as to be beneath the man, so I'll take a crack at it.
From the puff piece Chris reports on:
Couples who used analytical language, such as “think,” “understand,” “because,” or “reason,” during heated arguments were able to keep important stress-related chemicals in check, according to research published in the latest issue of the journal Health Psychology. Cytokines are inflammatory chemicals that spike during periods of prolonged tension and can lower your immunity and lead to early frailty, Type 2 diabetes, arthritis, and some cancers. The authors noted a curious gender twist in their results. Husbands benefitted from their wives’ measured language, but a man’s carefully chosen words had little effect on a woman’s cytokine balance.
So many things mixed in here: word counting, human biochemistry, language and the sexes. (By the way, "analytical language" is also referred to as "cognitive words", "measured language", "conflict-resolution words", and "cerebral words".) See Chris's posting for more details.