Universiteit Leiden

nl en

Shy parent, shy child?

Previous research has shown that extreme shyness is hereditary, but because shyness is such a broad concept it is difficult to identify specific genes. Anita Harrewijn has discovered particular brain measurements that can help. PhD defence 18 January.

Almost ten per cent of Dutch people will suffer from an anxiety disorder at some point in their lives. These people are afraid that others will think them strange or weird, or they are afraid of how they will react in particular social situations, such as when they have to face a group  of people, which might make them tremble or blush. 

Similarities in brain activity

Previous research has already shown that this kind of social anxiety disorder - or extreme shyness - is hereditary. Anyone who has extremely shy parents has a greater chance of developing the same symptoms. However, it is difficult to identify specific genes because social anxiety is such a broad term. In her PhD research, developmental psychologist Harrewijn shows that brain activity during an 'attack' of extreme shyness is also hereditary and is related to social anxiety. Clear similarities can be seen in the brain activity of family members who suffer from extreme shyness. 

Triggering shyness

For her PhD research Harrewijn studied a total of 134 people from nine different families where some members have a social phobia. Before the EEG scans of the brains were made, the researcher triggered a feeling of extreme shyness in the people taking part in the experiment. For the first task she told them that a photo of themselves would be judged by someone from their age group, and for the second they had to make a film about their good and bad characteristics; the film would be judged by someone of their own age.    

Cortical and subcortical areas

In fact, this judgement by peers never actually took place, but the threat alone was enough to raise the stress levels of the participants considerably. This could be seen in their brain activity shortly before making the film, which showed there was a raised level of activity between the cortical and subcortical areas in the participants with social anxiety. Harrewijn: ‘Whereas the cortical area mainly regulates control, the subcortical area deals with emotion. The two areas seem to be competing for attention.’

Copycat behaviour

‘These findings will help future research on the genetic background to social anxiety,' Harrewijn explains. 'This brain activity is more specific than the disorder, and is therefore probably influenced by fewer genes. Although the brain activity may be a matter of copycat behaviour rather than genetic similarities, it is quite probable that a child of extremely shy parents can also learn that behaviour. Follow-up research will be needed to show whether this brain activity can be seen in children before they develop a social anxiety disorder, so that we can help them at as early a stage as possible.'