Think about a time when you wanted to start exercising or eating healthier. Were you able to sustain this new behavior over time? If not, you are not alone. This discrepancy between an individual’s intended behavior and their actual behavior is known as the Say-Do Gap or the Intention-Behavior Gap.

In a review of past research, Sherran (2002) demonstrated that there is a gap between people’s intentions (what they say) and their behavior (what they do). Although both those who say they will act but don’t and those who say they won’t act but do could be responsible, Sheeran discovered it was the former group primarily driving the Say-Do Gap. For example, whereas 54% of people who intended to exercise did not follow through with their intention, only 3% exercised regularly despite having no such intention of doing so originally. Through this study, Sheeran demonstrated that even though intentions can predict many human behaviors and customer decisions, their relationship is not as strong as one would normally imagine. So, what makes individuals say they will do something and then not follow through?

When intentions and behaviors don’t line up

First, there is a wide body of literature that proposes that the Say-Do Gap exists because of various situational factors that prevent the intention from being translated into action. Blake (1999) asked respondents to identify the reasons or barriers that prevented them from taking part in environmentally sustainable activities, even though they had a general concern about the environment. The study revealed three main barriers to changes in recycling behavior – individuality (i.e., competing attitudes and motivations), responsibility (i.e., low perceived impact of individual action), and practicality (i.e., lack of time, money, resources). Individuals take these situational and practical factors into consideration at a much later stage and thus they influence their actions but not their intentions.

Second, there are also biases that come into play at the time of intention formation. This usually happens when people are asked questions about their engagement in socially desirable behaviors. Since exercising and recycling are considered socially desirable activities, people often construct their responses to portray themselves as someone who cares about personal health and the environment. This human tendency of constructing responses in a way that creates a more flattering image of themselves rather than answering truthfully and accurately is known as the Social Desirability Bias. Due to this bias, they overreport their socially desirable behaviors and under-report socially undesirable behaviors, creating a conflated image of themselves.

A great example of the Say-Do Gap and Social Desirability Bias put together is consumers’ perception towards electric cars. Studies suggest that even though 20% of people intend to purchase a battery electric vehicle, sales are just 7.5% in the entire UK car market. This highlights one situation where consumers may overreport their purchase intention to be considered “socially responsible”. However, their intention is not followed up because of certain situational factors which may arise at the moment of purchase, such as cost and time constraints, presence of better options in the market, affect, and so on.