While spanking is controversial, it was particularly concerning that these children were only 1 year old, the researchers noted, "a developmental stage when children are unlikely to understand the connection between their behavior and subsequent punishment and when spanking is more likely to cause physical injury."
Irritability and anger as common symptoms of depression may be implicated, Davis' group suggested.
They recommended that pediatric care providers be clear with fathers about inappropriate corporal punishment and give alternatives for handling problem behaviors in their children, as well as dealing with the dads' feelings of frustration and irritability.
Depression may also take away motivation or interest in reading to children -- an activity that may take focused effort compared with singing and playing games, they added.
The investigators cautioned that their cross-sectional, observational study could not determine causality or rule out residual confounding, and that paternal self-report of parenting behaviors may have been limited by recall bias or social desirability.
In addition, Davis and co-authors cautioned, while "depressed fathers may have been more likely to report adverse parenting behaviors because of low mood at the time of the survey," they did not see this pattern across all domains of parenting behaviors.