Model Basics

Self-Determination Theory (SDT) is a framework for the study of human motivation, personality and behaviour that encapsulates evidence from  6 “mini-theories”. SDT proposes that differences in behaviour can be explained by two central aspects: the extent to which people’s basic psychological needs are met, and the quality (rather than the quantity) of their motivation  

In the context of SDT, a person’s basic psychological needs are competence, autonomy, and relatedness [10,11]. Competence refers to a sense of mastery, feeling able to do the behaviour and interact with the context effectively. Autonomy has to do with a sense of volition and control (at least to an extent) of someone’s own life and behaviour. Relatedness refers to the human need to interact with, care, and be connected to others.

According to SDT, these needs are essential, inherent, distinct and universal. Social contexts that foster and encourage these basic psychological needs lead to people feeling a sense of growth, well-being, and intrinsic motivation, where the person behaves out of inherent interest or enjoyment. Social contexts that don’t encourage these basic psychological needs lead to frustration, alienation, diminished well-being and extrinsic motivation, where the person’s behaviour is controlled to a greater or lesser extent by external factors, rather than inherent enjoyment. 

In SDT, the type or quality of someone’s motivation – rather than the amount of motivation – is the key determinant of behaviour. This framework proposes that motivation moves along a continuum depending on whether the senses of competence, autonomy and relatedness are fulfilled or not. On one side of the continuum there is amotivation, which indicates a complete lack of motivation. On this side of the continuum people are less self-determined (they feel less competent, autonomous and related to others). Next in the continuum is external motivation, where motivation to act is controlled solely by external factors (e.g. paying for parking to avoid a fine). It has to do with compliance and seeking for external rewards or avoiding external punishment. Introjected motivation happens when the person knows that they should be acting in a certain way. It is somewhat externally controlled but there is an element of internalisation which is driven by wanting approval from oneself or others (e.g. joining the gym because you should be doing some exercise). When someone experiences identified motivation, they behave in a way that is consistent with their goals and their values, even if they don’t find the behaviour inherently rewarding, they just recognise that it’s important in order to achieve a greater goal (e.g. I go to the gym because improving my fitness is important to me). Integrated motivation occurs when external factors are fully internalised and agree perfectly with the person’s identity, even if they don’t act out of sheer enjoyment (e.g. I run because I am a runner). At the other side of the continuum, intrinsic motivation means that a person acts in a certain way simply because the behaviour is inherently rewarding to do; it feels good to do (e.g. spending time on a hobby). Intrinsic motivation is fully self-determined, people feel a sense of competence and fully choose to behave in that way. 

People who operate in more autonomous, self-determined contexts tend to develop more intrinsic motivational styles, which increase the chances of the person freely choosing to adopt and maintain the desired behaviour.

Model Strengths

✅ SDT is the most rigorous and evidence-based behavior change model on motivation.

✅ SDT has been successfully used to guide and contextualise interventions across a number of applied fields (e.g. education, healthcare or sports).

✅ SDT has been used in research across the world, and it has shown good cross-cultural relevance [12].

Model Weaknesses

⛔️ SDT lacks simple guidelines or processes for practical implementation. For example, how to move someone across the continuum of motivation.

⛔️ SDT may required specialist knowledge to be applied (e.g. use of scales to determine the level of autonomy)

⛔️ SDT only considers motivation and has to be combined with other models to cover all aspects of behavior change

Model Snapshot

Key takeaway

Competence, autonomy and relatedness are essential for behaviour change. Social contexts that fulfil these essential psychological needs lead to more internalised and higher quality types of motivation than contexts that don’t.

When to use this model

When you need to design behaviour change interventions focused on motivation. 

What you get from this model

A framework for understanding how to foster motivation that leads to behaviour change and maintenance. 

What you don’t get from this model

Although SDT-based interventions have been conducted in different settings, SDT doesn’t come with simple tools or guidelines for its implementation.

Extra Resources

🧠 For a long read on Self-Determination Theory from the original authors read: The "What" and "Why" of Goal Pursuits: Human Needs and the Self-Determination of Behavior

📢 For a comprehensive list of talks, lectures and podcasts on Self-Determination Theory explore: Center for Self-Determination Theory - Videos

📚 For a practical guide on how to use Self-Determination Theory as a design tool for behaviour change get: Engaged - Designing for behaviour change

🧠 For a long read on Self-Determination Theory from the original authors read: The "What" and "Why" of Goal Pursuits: Human Needs and the Self-Determination of Behavior

📢 For a comprehensive list of talks, lectures and podcasts on Self-Determination Theory explore: Center for Self-Determination Theory - Videos

📚 For a practical guide on how to use Self-Determination Theory as a design tool for behaviour change get: Engaged - Designing for behaviour change