“Acceptance means allowing our thoughts and feelings to be as they are, regardless of whether they are pleasant or painful; opening up and making room for them; dropping the struggle with them; and letting them come and go as they naturally do” (Harris, 2009; p134).

The purpose of acceptance is to allow ourselves to have painful private experiences if and when doing so allows use to act on our values. It is NOT about passively accepting our life situation (Harris, 2009; p134-135).

Most of the time when painful experiences and feelings happen we struggle against them. Our mind resists and rejects the experience in any number of ways such as getting angry, blaming ourselves or another person, wishing we could go back in time, trying to pretend it hasn’t happened, or distracting ourselves with activity. Some people try to dull emotional pain with drugs, change emotional pain into physical pain by harming themselves, or lash out at the world by damaging things or picking fights other people. This is called experiential avoidance. 

Acceptance involves dropping all of these kinds of strategies and allowing the painful feelings and experiences to be as they are. It does not mean liking them or embracing them. It simply means making space for them. 

Many different terms are being used to refer to the concept of acceptance. Some of these include: letting go; opening up; creating space for it, making room for it; expanding around it; stop fighting with it; making peace with it; letting it be; dropping the struggle; breathing into it.

Acceptance and defusion are quite similar and they go hand in hand. They both involve opening up and making space. When we defuse from a thought we accept it and when we accept a thought we defuse from it. Acceptance is easier to understand and practice if we have already done some work on defusion (Harris, 2009; p140)

Acceptance is different from resignation, tolerance or passively putting up with any and every unpleasant situation. In contrast, ACT advocates taking action to improve our life situation as much as possible. The purpose of acceptance is to counteract experiential avoidance when it has become a barrier to values-congruent action (Harris, 2009; p135). There is no need for acceptance of situations or behaviours that are readily changed (Hayes and Smith, 2005) [see Note H5i].

Willingness is another word or synonym for acceptance offered by Hayes and Smith (2005). The ancient meaning of the word willing is to choose, and these authors talk about willingness and acceptance as a very active orientation. “[T]he words willingness and acceptance mean to respond actively to your feelings by feeling them, literally, much as you might reach out and literally feel the texture of a cashmere sweater…. To be willing and accepting means to respond actively to memories by remembering them … to respond actively to bodily sensations by sensing them …Willingness and acceptance mean adopting a gentle, loving posture toward yourself, your history, and your programming so that it becomes more likely for you simply to be aware of your own experience, much as you would hold a fragile object in your hand and contemplate it closely and dispassionately” (Hayes and Smith, 2005; p45). 

“The goal of willingness is not to feel better …the goal of willingness is to feel all of the feelings that come up for you more completely, even - or especially - the bad feelings, so that you can live your life more completely" (Hayes and Smith, 2005; p45).

Research has shown that willingness to experience pain – both physical and emotional – is associated with greater tolerance of pain, better functioning, and in the case of anxiety, reduced levels of this particular type of painful experience (Hayes and Smith, 2005; p46). Conversely, the experiential avoidance predicts a gradual worsening of quality of life over time (p49).