Up and down the land parents and teenagers are engaged in tense negotiation and diplomacy in an effort to maintain domestic peace. Some households are finding more success than others. Their secret, according to a new paper in NeuroImage, is a literal meeting of minds – synchronisation of brain cell firing seems to foster emotional harmony. Moreover, when parents and their teenagers display this “neural similarity”, write Tae-Ho Lee and his colleagues, “this promotes youths’ psychological adjustment”.
These are intriguing findings – in the fact the researchers claim this is the first time that anyone has compared the brain activity of parent-child dyads with their interpersonal relations. However, sceptics will baulk at the rampant neuro-reductionism and at the paper’s repeated claims of brain-based causation on the basis of purely correlational evidence.
The researchers recruited 31 teens and their primary caregiver. The latter was always either the teen’s mother or father, genetically related to them. The average age of the parents was 43 years and just under 90 per cent were mothers. The teens were a roughly 50-50 mix of boys and girls, with an average age of 15.
Each parent and teen participant underwent a 6-minute brain scan in which they lay still and looked at a cross on a screen. From this, the researchers identified each person’s resting state “connectome” showing the patterns of neural firing across the brain and the functional connectivity between 13 different brain networks (the researchers described this as showing each participant’s “unique brain fingerprint”).
For two weeks, every teen and parent also kept a daily diary, reporting their positive and negative moods. The teens also completed an “emotional competence” questionnaire about their ability to identify and describe their feelings.
Ho Lee and his team looked at the emotional synchrony between each parent-child dyad – whether they tended to report the same kinds of emotions each night or not – and found plenty of variability. Some dyads showed a lot of similarity, others were completely out of kilter. The researchers also looked at the level of similarity in the brain connectomes of each parent-teen pair, finding that some were more “neurally in-tune” than others.
The two measures correlated, as in the parent-teen pairs who showed greater emotional synchrony also tended to show greater neural synchrony. “We propose that children’s neural connectome is a psychological representation at the neural systems level, resulting from shared experiences with their primary caregiver,” the researchers said.
There was also a correlation between greater neural synchrony between parent and teen and the teen’s level’s of emotional competence.
Next, the researchers conducted a mediation analysis, which is a statistical technique for testing how factors might be associated. This showed that neural synchrony was linked to greater emotional competence via emotional synchrony (consistent with the possibility that neural similarity fosters emotional synchrony, which leads to greater emotional competence). In contrast, the analysis suggested that neural synchrony did not mediate the association between parent-teen emotional synchrony and teens’ emotional competence (in other words, this is not consistent with the idea that emotional synchrony breeds neural synchrony, which fosters greater emotional competence).
Based on this, the researchers made repeated causal claims, such as: “dyadic brain similarity plays an important role in children’s emotional competence by contributing to more synchronised emotional mood fluctuations”; and “We provide the first empirical evidence unpacking how the brain’s functional organisation is shared between individuals and influences emotional synchrony, ultimately conferring benefits for youths’ development”; and “the degree of neural similarity in parent-child dyads promotes youths’ psychological adjustment” (all emphases added).
However, this is a purely correlational study so there’s no way to know if any of the factors – parent-teen emotional synchrony, parent-teen neural synchrony, teen emotional competence – are causally related. Mediation analysis is no substitute for data derived from longitudinal and/or experimental methods. Yes, it is fascinating to see how complex emotional relations between parents and their teens may manifest at a neural level, but it seems overly reductionist and simplistic to claim that brain activity is the root cause of everything else.
Even assuming that neural synchrony between parents and teens really is an important influence on parent-teen harmony and teens’ psychological adjustment, it’s hard to imagine, from a clinical or everyday perspective, that this is a particularly useful or practical level at which to think about or intervene in family life.