The neurostatistical precursors of noise-magnifying statistical procedures in infancy

David Allison points us to this paper, The neurodevelopmental precursors of altruistic behavior in infancy, by Tobias Grossmann, Manuela Missana, and Kathleen Krol, which states:

The tendency to engage in altruistic behavior varies between individuals and has been linked to differences in responding to fearful faces. The current study tests the hypothesis that this link exists from early in human ontogeny. Using eye tracking, we examined whether attentional responses to fear in others at 7 months of age predict altruistic behavior at 14 months of age. Our analysis revealed that altruistic behavior in toddlerhood was predicted by infants’ attention to fearful faces but not happy or angry faces. Specifically, infants who showed heightened initial attention to (i.e., prolonged first look) followed by greater disengagement (i.e., reduced attentional bias over 15 seconds) from fearful faces at 7 months displayed greater prosocial behavior at 14 months of age. Our data further show that infants’ attentional bias to fearful faces and their altruistic behavior was predicted by brain responses in the dorsolateral prefrontal cortex (dlPFC), measured through functional near-infrared spectroscopy (fNIRS). This suggests that, from early in ontogeny, variability in altruistic helping behavior is linked to our responsiveness to seeing others in distress and brain processes implicated in attentional control. These findings critically advance our understanding of the emergence of altruism in humans by identifying responsiveness to fear in others as an early precursor contributing to variability in prosocial behavior.

Allison writes:

From the paper, I discern that stepwise regression was used, but could not determine how many variables were used and whether any adjustment to the reported significance levels to accommodate the overfitting that is known to occur with stepwise selection was used. This raises questions when interpreting the results.

Also, they’re making the classic error of labeling differences as real if they’re statistically significant and zero if they’re not. That’s a standard statistical technique, but it’s a disaster; it’s a way to add noise to your study and get overconfidence.

I assume the authors of this paper were doing their best, but I’m very doubtful that they’ve offered real support for their claim that their findings “critically advance our understanding of the emergence of altruism in humans.” That’s a bit over the top, no?