Textbooks make claims like this:
“Babies whose mothers deliberately attract attention to themselves and then smile when their babies look towards them are more likely to show a general preference for smiling faces. On the other hand, the infants of mothers who are depressed (and who therefore are less likely to smile) are poorer in discriminating smiling from non-smiling faces than are infants of non-depressed mothers.”
Should you believe this? I examine
Bornstein, M. H., Arterberry, M., Mash, C., & Manian, N. (2011). Discrimination of Facial Expression by 5-Month-Old Infants of Nondepressed and Clinically Depressed Mothers. Infant Behavior & Development, 34(1), 100–106.
And a correction to it, to find out.