Using a population-based sample of 1394 toddler-aged twins, we studied tactile and auditory defensiveness, as reported by mothers. Symptoms were fairly normally distributed, with some accumulation of cases in the extreme range. Girls were over-represented in the extreme tactile defensive group. Both auditory and tactile defensiveness was associated with fearful temperament and anxiety. Twin correlations for the full range of scores and concordance rates for the extremes suggested a moderate influence for genetic factors, with some suggestion that the tactile domain might be more heritable and that genetic influences might increase with severity. Bivariate genetic analysis indicated that largely different genetic factors contributed to individual differences in auditory and tactile defensiveness.

Childhood Disability Update 2005 - Conference Abstracts.Pediatric Oncall [serial online] 2006 [cited 15 January 2006(Supplement 1)];3. Available from:
http://www.pediatriconcall.com/fordoctor/Conference_abstracts/
Auditory_Defensiveness.asp