The diathesis stress approach to mental illness proposes that neither environmental stress alone nor genetic factors alone are enough to produce mental illness. Instead, both environmental stress and genetic predisposition to mental illness are required for mental illnesses like schizophrenia and depression to be expressed. In a recent test of this idea (Sachs, Ni, & Caron, 2015), either normal rats or rats that were genetically modified to have low levels of the neurotransmitter serotonin received either no social stress or a social stress treatment. Researchers measured the number of social interactions produced by subjects after the stress treatment. Data like those observed by the author are listed below. Use a two-factor ANOVA with α = .05 to evaluate the data.

Transcribed Image Text:

Factor A: Stress Social Stress None Low serotonin 0 8 11 Factor B: Gene 5 8 10 19 12 22 20 15 20 High serotonin 15 17 23 14 16 23 10 16 17 17 23 19