Table 1.

Examples of associations between behaviour and telomere length in humans.

behaviour type	sample	behavioural measure	tissue	result	references
impulsivity (i.e. impatience, steeper time discounting)	Chinese undergraduate students	preference for smaller sooner versus larger later financial reward	leucocytes	greater impulsivity associated with shorter telomeres	[1]
	children with ADHD	hyperactive–impulsive symptoms (assessed via structured interview of parents)	leucocytes	higher levels of hyperactivity–impulsivity associated with shorter telomeres	[2]
risk-proneness (i.e. strength of preference for a riskier option)	Chinese undergraduate students	decision of how much to invest in an experimental stock	leucocytes	higher risk proneness associated with shorter telomeres	[1]
physical activity	systematic review of 37 studies	all forms of exercise	varied but mostly leucocytes	tendency for exercise to be associated with longer telomeres	[4] see also [5]
	British white twins	physical activity in leisure time	leucocytes	less physical activity associated with shorter telomeres	[6]
	American men and women (NHANES)	running	leucocytes	meeting physical activity guidelines from running associated with longer telomeres	[7]
	less physically active white and African-American women	accelerometer-measured sedentary time	leucocytes	higher sedentary time associated with shorter telomeres	[8]
eating (amount and/or frequency)	meta-analysis of 16 studies	body mass index (BMI)	leucocytes	higher BMI associated with short telomeres	[9]
	meta-analysis	obesity (multiple measures)	mostly leucocytes	tendency for higher BMI/obesity to be associated with shorter telomeres	[4]
smoking	systematic review of 84 studies and meta-analysis of 30	ever versus never smokers and pack years smoked	varied but mostly blood	smoking associated with shorter telomeres. More pack years smoked associated with shorter telomeres	[10]
alcohol consumption	middle-aged, Finnish businessmen	past alcohol consumption	leucocytes	more alcohol consumption associated with shorter telomeres	[11]
stress reactivity	American kindergarten children (5–6 years)	heart rate, salivary cortisol, internalizing behaviours	buccal cells	higher heart rate, cortisol and internalizing behaviours associated with shorter telomeres	[12]
	community sample of carer and non-carer American women	cortisol responses to acute stress (Trier Social Stress Test), overnight urinary-free cortisol, diurnal basal cortisol slope	PBMCs	higher cortisol responses to an acute stressor, higher overnight urinary-free cortisol and flatter daytime cortisol slopes associated with shorter telomeres	[13]
neurotic personality type	population cohort study	neuroticism scale of Eysenck Personality Questionnaire	leucocytes	higher neuroticism associated with shorter telomeres	[14]
pessimistic personality	post-menopausal American women	questionnaire (Revised Life Orientation Test)	leucocytes	higher pessimism associated with shorter telomeres	[15]