Hemispheric lateralisation and immune function: a systematic review of human research.

Past studies examined relationships between hemispheric lateralisation (HL) and immune system functioning. However, there has been no up-dated systematic review of this research area. This article reviews relevant published studies, evaluates study quality and effect sizes. Eleven studies were selected: three revealing a relationship between weaker left hemisphere function and poorer immune function, three describing a relationship between weaker right hemisphere function and stronger immune functioning, and five describing both relationships. Mean effect-size of the studies was r=0.536 (range 0.280-0.866). Collectively, studies point at left-HL and stronger immunity relationships. Limitations, mechanisms and clinical implications are discussed.