"what can be asserted without evidence can also be dismissed without evidence"

It's on the person who is implying a causation to state why they think that there is such a causal relationship.

Marriage success and child success have so many other things that they are correlated to: Home ownership, IQ, wealth, zip code, parental educational background, ability to talk about feelings, empath, conflict skill, ...,

So somebody comes around and picks "Marriage" out of this huge list, and somehow now the burden is supposed to be on the listeners to disprove it?