For example, an implicit theory of stability is often invoked when assessing political allegiances, therefore if this allegiance actually changes, recollection of past allegiance will be incorrect, and assumed to be the same as the current political identification. An implicit theory of change is invoked when a change in an attribute over time is expected. One example of this is a study by Conway and Ross, which demonstrates that if a change in skill is expected, but there is no actual improvement, people will believe that their past skill state was worse than it was. In general recollection of pain is fairly accurate, although differences are seen between recollection of acute and chronic pain. Research suggests that recall for acute pain is more accurate than recall for chronic pain. An interesting phenomenon seen in recollection of pain in the self is the peak-end phenomenon. Research has shown that when enduring painful experiences, people will 'prefer' more drawn out experiences that end with lower levels of pain, over shorter experiences that end with higher levels of pain, even though the shorter experiences provide less pain overall. Recalled ratings of pain are more closely related to a combination of the peak pain in the experience, and the end pain of the experience. Whilst the length of the experience factors in very little, there is a 'duration neglect' when recollecting painful experiences. Symbolic interactionism stresses the 'social construction of an individual's sense of self' through two main methods: 'In part the self emerges through interaction with others...But the self is a product of social structure as well as of face-to-face interaction'. This aspect of social psychology emphasizes the theme of mutual constitution of the person and situation. Instead of focusing on the levels of class, race, and gender structure, this perspective seeks to understand the self in the way an individual lives their life on a moment-by-moment basis. Social psychology acknowledges that "one of the most important life tasks each of us faces is understanding both who we are and how we feel about ourselves". This allows us to better understand ourselves, abilities, and preferences so that we are able to make choices and decisions that suit us best. However, rather than absolute knowledge, it would seem that 'a healthy sense of self calls for both accurate self-knowledge and protective self-enhancement, in just the right amounts at just the right times.' In dynamical social psychology as proposed by Nowak "et al.", the self is rather an emergent property that emerges as an experiential phenomenon from the interaction of psychological perceptions and experience.