One consistent characteristic for humans is our inclination to categorize groups of people – which then leads to the problematic tendency to discriminate between group members. The source of much human suffering lies in the act of people developing prejudice against an individual because of their group membership. There is a significant impact that prejudice has on the health and safety of its victims making it an important, socially significant issue to be addressed from many different angles including behavior science.

Human prejudice is defined as the objectification and dehumanization of people as a result of their participation in evaluative verbal categories (Hayes et al., 2002). Essentially, language and verbal processes make acts of prejudice possible because we use it to organize information about others.

 It is impossible to exist without some sort of bias; implicit bias is when we have attitudes or associations about people or a group of people that we are unaware of or which are automatic. These unconscious actions can have the potential to influence behavior in multiple ways.

In Robin DiAngelo’s book White Fragility, she suggests that it is not possible to free oneself entirely from bias. When we live within a culture that upholds structures of systemic racisms, we will be influenced by that culture. We know that environment shapes behavior, and bias and prejudice are not exempt. DiAngelo points out that racism is the norm rather than an aberration; it is in the air in which we breathe. Understanding this allows us to focus on how, rather than if our bias manifests.

When faced with the difficult reality of our own prejudice, avoidance or suppression of difficult thoughts and feelings can be a normal reaction. However, research on the effects of thought suppression shows that it can often be ineffective (Hausmann & Ryan, 2004). When people attempt to suppress prejudiced thoughts, it may lead to an increase in those thoughts. Don’t think about a purple elephant! What’s on your mind now?

Rather than attempting to avoid, deny or suppress prejudiced thoughts, a more effective strategy may be to apply strategies based in acceptance and commitment therapy (ACT). Mindfulness, cognitive defusion, acceptance, and valued action are ACT processes which can address prejudice and increase psychological flexibility. ACT is an action-oriented approach which aims to build acceptance and mindfulness skills. It strives to build awareness of one’s experiences, both comfortable and uncomfortable, while choosing to engage in meaningful actions in the midst of those experiences. ACT challenges the verbal processes, categorizations and evaluations made about self and others which is why it can be particularly useful to address prejudice. 

Research suggests that the key approaches to addressing prejudice include teaching awareness and flexibility with ones prejudice thoughts while discouraging thought suppression strategies. Another key is to emphasize internal motivation rather than external motivation for reducing prejudice; i.e., connecting to your personal values as a means for motivation rather than via social motivation. Additionally, promoting perspective-taking and empathy are key strategies as well as encouraging contact, cooperation and interactions between groups (Masuda, Hill, Morgan, & Cohen, 2012).

In 2007, Lillis and Hayes compared two approaches to reducing racial and ethnic prejudice among college students: a session based on acceptance and commitment therapy (ACT) and an educational lecture from a psychology textbook on racial differences. Results indicated that the ACT intervention produced significantly more change in overall scores and was more effective in increasing positive behavioral intentions at follow-up.

The workshop focused on a range of exercises with students which included:  a) to become mindfully aware of their own prejudicial thoughts and feelings and reactions, (b) to accept those thoughts and feelings as the natural result of learning and using language in a prejudicial society, (c) to notice the automatic processes of evaluation and judgment more generally, and (d) to orient to positive actions consistent with their own values regarding how to treat other human beings.

Workshop leaders pointed out how stigma is built into our normal use of language and cognitive processes but by changing your relationship to those thoughts you can more flexibly respond. During the workshop, there was discussion around noticing the process of automatic thinking. For example, students were asked to fill in sentences such as, “there’s no place like ___”  to illustrate how thinking can be automatic. This tendency becomes problematic when it comes to thoughts about other groups of people. But rather than trying to change those automatic thought processes, workshop leaders helped students become mindfully aware of the presence of those thoughts and reactions while focusing on behaviors that were consistent with one’s values. They were encouraged to notice the ongoing process of judgment and evaluation but attend less to that content and more to the actions and behaviors that were consistent with their values.

Becoming mindfully aware of your prejudice thoughts and behaviors can be an uncomfortable experience. The key to moving forward is what we do with that discomfort. We can choose to use that discomfort as the fuel for actions – actions that can enact real change.

It is clear that ACT offers a valuable approach in dealing with prejudice behavior and can help shape intrinsic, pro-social behaviors to reduce prejudice actions. ACT processes such as building mindfulness, cognitive defusion, acceptance, and valued action are effective strategies for fighting against prejudice and injustice which behavior science has a responsibility to address. 


Hausmann, L.R.M. & Ryan, C.S. (2004). Effects of external and internal motivation to control prejudice on implicit prejudice: The mediating role of efforts to control prejudiced responses. Basic and Applied Social Psychology, 26, 215-225.

Hayes, S. C., Niccolls, R., Masuda, A., & Rye, A. K. (2002). Prejudice, terrorism and behavior therapy. Cognitive and Behavioral Practice, 9(4), 296–301.

Lillis, J., & Hayes, S. C. (2007). Applying acceptance, mindfulness, and values to the reduction of prejudice – A pilot study. Behavior Modification, 31, 389- 411.

Masuda, A., Hill, M. L., Morgan, J., & Cohen, L. L. (2012). A psychological flexibility-based intervention for modulating the impact of stigma and prejudice: A descriptive review of empirical evidence. Psychology, Society, & Education, 4(2), 211-223. Available at: