State and trait variance in salivary α-amylase: A behavioral genetic study

Dorothée Out, Marian J. Bakermans-Kranenburg, Douglas A. Granger, Christa M. Cobbaert, Marinus H. van Ijzendoorn

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


This is the first behavior genetic study of salivary α-amylase (sAA), focusing on genetic and environmental influences on stability and change in sAA during baseline and exposure to infant crying. The sample consisted of 184 adult twin pairs. Although there was significant variation between individuals in basal levels of sAA and in responsivity to infant crying, strong stability in sAA concentrations across conditions was found. Similar genetic mechanisms influenced sAA at baseline and in response to cry sounds (explained variance: 51-62%), accounting for part of the stability in sAA. Unique environmental factors explained the remaining variance in sAA, some of them only emerging in response to the cry sounds, explaining individual differences in the pattern of reactivity. These findings confirm that sAA is sensitive to the effects of potentially stressful stimuli (state variance) and at the same time demonstrate its relative robustness and stability across time and conditions (trait variance).

Original languageEnglish (US)
Pages (from-to)147-154
Number of pages8
JournalBiological Psychology
Issue number1
StatePublished - Sep 2011


  • Behavior genetics
  • Genes
  • Infant crying
  • Salivary α-amylase
  • Twins

ASJC Scopus subject areas

  • General Neuroscience
  • Neuropsychology and Physiological Psychology


Dive into the research topics of 'State and trait variance in salivary α-amylase: A behavioral genetic study'. Together they form a unique fingerprint.

Cite this