It is an all-too-common scenario—a baby is up all night crying, and an exhausted mother gets in and out of bed to care for the infant. The father sleeps soundly next to her, seemingly oblivious to the crying baby. In the morning, the father is shocked to hear that it was a “bad night” and insists that he didn’t even hear the baby crying.
So, can research help us to settle this age-old debate—are men really less likely to hear babies crying at night? Is this simply a biological difference in hearing sensitivity, or is there something more going on here?
A recent study finally addressed this debate. Here is what they found:
Men are slightly less likely than women to awaken to quiet crying sounds but are just as likely as women to awaken to louder crying sounds. The researchers found a very slight difference at the lowest decibel level (33 to 44 decibels—which is a little bit louder than a whisper), with women being 14 percent more likely than men to awaken to both crying sounds and alarms at this level. However, at higher decibel levels (which would likely be the actual decibel level of an infant crying on a baby monitor or in the same room), there were no differences in waking between men and women.
Mothers wake up with infants about three times more than fathers. This study found that mothers woke up more frequently than fathers in most families. Only about 23 percent of families reported that mothers and fathers woke up an equal number of times at night. Only 1 percent of families reported that the father woke up more often than the mother. This finding backs up previous research, which consistently finds that women wake up with infants more often than men, even when controlling for breastfeeding and whether both parents are employed outside of the home.
The very slight difference in hearing sensitivity between men and women cannot explain the significant differences in mothers versus fathers waking up with their infants. Based on the very slight difference in hearing sensitivity, it was predicted that mothers should do 57 percent of the nighttime wake-ups. Yet, this study found that mothers do 76 percent of the wake-ups, suggesting that factors other than hearing sensitivity might be at play.
Why Might This Be?
So if it isn’t that fathers don’t hear the crying, why are women waking up with infants so much more often than men? Breastfeeding is obviously a huge factor, but research also finds that breastfeeding doesn’t fully explain these differences. Differences in parental leave and societal expectations likely also play a role. Interestingly, this study was conducted in Denmark, which has generous and gender-neutral parental leave policies (24 weeks for each parent) and more egalitarian views on gender roles. The differences in nighttime caregiving between men and women in countries like the United States are likely to be even more striking.
Important Note
This study only examined hearing differences in men and women who were not yet parents to look at whether there was a basic biological difference in hearing independent of societal expectations, gender roles, and conditioning to respond to infant cries. However, hormonal changes during pregnancy and postpartum may change the brains of mothers to make them more attuned to infants’ cries. For example, research also finds that the hormones released during breastfeeding make mothers more sensitive to infant cries. Mothers may also become more attuned to infant crying due to habitually responding to the crying more often. In other words, just because there is not a biological difference in hearing sensitivity between men and women does not mean that mothers are not more attuned to infant cries.
In addition, simply being able to hear crying is different than waking up and becoming alert enough to care for the infant. Research finds that when women hear crying, their brain is more likely to shift out of resting state to a more attentive state, while men’s brains tend to stay in resting state. It may be that men hear the crying but do not spring to action in the same way as women.
Should Fathers Be Doing More of the Night Shift?
This study shows us that mothers still do the bulk of nighttime wake-ups with infants, even in more egalitarian societies. However, a significant body of research finds that fathers taking a bigger role in nighttime caregiving may have huge benefits for the whole family. First and perhaps most importantly, the more nighttime caregiving that fathers do, infants wake up less often at night, and they show better sleep quality. Not surprisingly, fathers being more involved is also linked to better outcomes for mothers—including less insomnia, being happier with their relationship, and more confidence about their child’s sleep. Finally, in families with more equal sharing of nighttime caregiving, the fathers report stronger bonds with their infants.
Overall Translation
Mothers still seem to do most of the nighttime wake-ups with infants, and this difference does not seem to be explained by basic biological differences in hearing sensitivity between men and women. It also doesn’t seem to be fully explained by breastfeeding or the employment status of mothers. Yet, despite this enduring gender difference, research also finds that infants and their families would benefit from fathers doing more of the nighttime care—whether they are the first to hear the crying or not.
