TABLE 1.

Self-affirmation comparison studies on proximal and behavioural outcomes.

Study	Approaches compared	Target behaviour	Proximal outcome change	Behaviour change
Armitage et al. (2011)	Implementation intention, Kindness	Alcohol consumption	Both increased defensiveness	Both decreased alcohol consumption
Celeste et al. (2021)	Values,a Dual (Ethnic/British) identity,b British identity	Test scores	N/A	Dual-identity affirmation increased scores among Black students, Values affirmation increased scores among non-Black students (primarily Eastern European and South Asian) and decreased scores among Black students
Choi and So (2019)	Values, Message-integrated positive trait	Environmentally conscious action (e.g., recycling)	When viewing a high-threat message, both increased perceived risks, attitude and intention	N/A
Critcher and Dunning (2015)	Values, Perspective	Test scores	Both reduced defensiveness	N/A
Harris et al. (2014)	Values, Implementation intention, and a combination condition	Fruit & vegetable intake	None had an effect on intentions	All increased fruit/vegetable consumption
Iles et al. (2021)	Values essay, Health essay, Other-affirmation essay,c Values questionnaire, Health questionnaire, Other-affirmation questionnaire, Kindness questionnaire, Self-activationd	Alcohol consumption	Comparisons: Self- vs. Other-affirmations Self-affirmations associated with greater odds of creating an action plan to reduce alcohol consumption Values vs. Health-affirmations Values-affirmations associated with greater odds of creating an action plan to reduce alcohol consumption Essay vs. Questionnaire Essay affirmations associated with more worry and greater intentions to reduce consumption Self-affirmation vs. Self-activation Self-affirmation associated with less endorsement of the message and perceived importance of following health guidelines, but greater intentions to reduce consumption	N/A
Jessop et al. (2009)	Values, Kindness, and Positive trait	Sunscreen use	All led to more positive attitudes	Only positive trait affirmation increased sunscreen acceptance
Jiang (2018)	Values, Work affirmation	Creativity (Slogan Generation)	N/A	Both attenuated the negative effect of high job insecurity on creativity
Knight and Norman (2016)	Values, Kindness, and Positive attributes	Binge drinking	None led to differences in attitudes or intentions	None led to behaviour change
Norman and Wrona-Clarke (2016)	Values, Implementation intention, and a combination condition	Binge drinking	None led to differences in defensiveness or intentions	Implementation intentions reduced binge drinking
Shnabel et al. (2013)	Values, Social belonging	Test scores	N/A	Only social belonging improved test scores
Vogt et al. (2021)	Implementation intention, Kindness questionnaire	Alcohol consumption	Neither led to differences in message acceptance, perceived risks, intentions, or action plans	Neither led to behaviour change
Zhu and Yzer (2021)	Values, Positive attributes	Alcohol consumption	Both reduced defensiveness, increased message acceptance	N/A

Note: Only studies containing multiple self-affirmation interventions, a control, and a threat included.

^a“Values” indicates a values essay affirmation unless otherwise noted.

^bDual-identity affirmation aims to simultaneously affirm both ethnic identity and common national identity among students.

^cOther-affirmation entails thinking of a value important to oneself and how a close other has demonstrated that value.

^dSelf-activation is induced by having participants circle all instances of the letter “i” in a paragraph.