Study: Couples May Not Communicate Better Than Strangers (PsychCentral):
“Although speakers expected their spouse to understand them better than strangers, accuracy rates for spouses and strangers were statistically identical. This result is striking because speakers were more confident that they were understood by their spouse” […]
“A wife who says to her husband, ‘it’s getting hot in here,’ as a hint for her husband to turn up the air conditioning a notch, may be surprised when he interprets her statement as a coy, amorous advance instead,” said Savitsky, who is lead author of the paper, published in the January issue of the Journal of Experimental Social Psychology.