Main concepts and definitions of terms

As the name suggests, the Model of Human Occupation was established to explore, organize and make explicit the concept of human occupation, which was considered the foundation of occupational therapy. The model has undergone substantial changes since its original publications in the early 1980s and many of these changes are detailed in the historical description section of this chapter. This section discusses the major concepts as they were presented in the fourth edition of the major text (Kielhofner, 2008).

In the fourth edition, Kielhofner (2008) stated, “The vision for MOHO has been to support practice throughout the world that is occupation-focussed, client-centred, evidence-based, and complementary to practice based on other occupational therapy models and interdisciplinary theories.” (p. 1.) In some ways the model is difficult to describe, because it has evolved substantially in its concepts, since the first edition of the text in 1985, whilst keeping its original structural components.

It is difficult to identify the overall purpose of MOHO in its current (and previous) edition as these latest writings have highlighted the model’s newest developments and changes, without necessarily making explicit the model’s purpose. However, to use the metaphor of the window through which one looks without making the process of looking out the window explicit, it may be that MOHO centres on the processes of occupational adaptation, without stating it overtly. The core concepts of the model were listed as “environmental impact, volition, habituation, performance capacity, participation, performance, skills, occupational identity, and occupational competence” (Kielhofner, 2008, p. 145). Figure 6.1 shows how their relationships are organized, with all of the concepts leading to occupational adaptation. Therefore, occupational adaptation might be the overall focus of MOHO.

FIG 6.1 The process of occupational adaptation.

(adapted from Kielhofner, 2008, p. 108)

Figure 6.1 outlines how a person engages in human occupation within the context of the environment and this process results in occupational adaptation. Three concepts are considered to be internal to the person. These are volition, habituation and performance capacity and are concepts that have been associated with MOHO since its origins. Additionally, human occupation is conceptualized as having three dimensions. These are participation, performance and skill. When a person engages in occupation, it creates a change in occupational identity and occupational competence, both of which are conceptualized as the components of occupational adaptation. All of this occurs in the context of an environment that shapes and is shaped by all aspects of the process.

The first aspect of the model that we will describe is the original concepts associated with MOHO − volition, habituation, performance capacity and environment (Figure 6.2). Kielhofner (2008) stated that MOHO aims to provide a framework for conceptualizing how people “select, organize and undertake their occupations” (p. 12). An earlier version of the model described this aim as the parallel concern for how occupation is “motivated, patterned and performed” (Kielhofner, 2002, p. 13). The model attends to each of these aims through the concepts of volition, habituation and performance capacity, respectively. That is, volition explains why people select occupations, habituation outlines how they organize their occupations and performance capacity attends to the skills and abilities that enable them to perform their occupations. Human occupation is also conceptualized as existing within an environmental context that influences all aspects of occupation. These environments provide opportunities, as well as support, demand and constrain occupation. In discussing environment, the model details physical and social environments and uses the term occupational settings to refer to the overall context surrounding occupation.

FIG 6.2 The basic concepts of human occupation.

Volition

The concept of volition is finely detailed in MOHO. This is one of the unique features of the model, as this level of detail about volition does not occur in any of the other models. The human need to act is presented as pervasive, intense and the basis for occupation. The model uses the term volition to refer to this impetus towards action. Kielhofner (2008) defined volition as “a pattern of thoughts and feelings about oneself as an actor in one’s world which occurs as one anticipates, chooses, experiences, and interprets what one does” (p. 16). MOHO presents volitional thoughts and feelings as including three components − personal causation, values and interests – and a volitional process that includes a cycle of anticipation, making choices, experience and interpretation. Each of the three components of volition is influenced by this volitional cycle, in which volition affects how people anticipate action, make choices about what action they will engage in, experience action and interpret or give meaning to their actions. Each of these components of volition also comprises other elements.

First, personal causation refers to “one’s sense of capacity and effectiveness” (Kielhofner, 2008, p. 13). The term personal causation is used in the sense that people can experience themselves as being able to cause or make things happen, that is, to be able to act purposefully in the world and produce outcomes. Personal causation is conceptualized as comprising two elements, a sense of both personal capacity and self-efficacy. These refer respectively to people’s thoughts and feelings about what they are capable of and their sense of what kinds of outcomes they are able to control. It may be that people’s sense of personal capacity pertains to something that is within them (but affects how they operate within the world), whereas self-efficacy operates more overtly in their relationships with the world. While people can experience a sense of capacity, they can also encounter incapacity, which “is experienced as difficulty doing the things that matter in one’s life” (p. 37).

Self-efficacy requires both self-control and a sense of being able to bring about a desired outcome. It relates to specific spheres of life, in that people might feel they can control outcomes in some areas more than others (Kielhofner, 2008). Experiences contribute to the development of both personal capacity and self-efficacy in that people are more likely to persist or seek out opportunities in situations in which they feel capable or efficacious and to avoid situations that do not provide that kind of feedback or outcome. Often, the sudden or gradual loss of personal capacities leads to a reduced sense of self-efficacy, just as the contexts in which people conduct their lives can enhance or reduce their self-efficacy.

Second, MOHO presents values as contributing fundamentally to the volition for action. Values are the “beliefs and commitments” that people develop about “what is good, right, and important to do” (Kielhofner, 2008, p. 39). The values that individuals hold are developed in relation to the broader culture in which they have grown up and live. Kielhofner suggested that, as values are developed from cultural norms, people develop a sense of belonging to the cultural group when acting in ways that are consistent with their values and experience guilt and shame when acting in contravention of those values.

MOHO associates two concepts with values. These are personal convictions and a sense of obligation. Respectively, these link values to the worldviews that people hold and the actions they are likely to take. Kielhofner (2008) defined personal convictions as “strongly held views of life that define what matters” (p. 40). Personal convictions are more than what people believe and include their worldviews and perspectives. That is, they are what persons believe to be important. Whereas some aspects of a worldview might be relatively easy to change, personal convictions about what matters are not. MOHO also emphasizes the connection between values and action. Kielhofner (2008) suggested that “values bind people to action” (p. 41) through a sense of obligation to act in ways that are consistent with their values. Therefore, self-esteem and sense of self-worth can be reduced when people’s ability to perform is not consistent with their values or those of the society (where those societal values matter to them). In addition, where enduring changes to people’s capacities occur (which change their ability to act in the world), the need for action and values to be consistent can prompt a process of revising one’s values.

The third aspect of volition is interests. This concept relates to those things that people find enjoyable or satisfying. As Kielhofner (2008) stated, “interests reveal themselves both as the enjoyment of doing something and as a preference for doing certain things over others” (p. 42). Enjoyment can derive from any constellation of factors including bodily pleasure, fulfilment from intellectual and artistic pleasures, the handling of materials and production of something pleasing, and fellowship with others. Kielhofner associated the attraction individuals might have to particular occupations with the concept of “flow” (Csikszentmihalyi, 1990). In flow experiences, people are engaged deeply in something and often experience a sense of timelessness. Flow experiences result when the demands of the activity or occupation optimally match the capacities of the individual. The implication is that enjoyment (and, therefore, interest) typically increases when individual capacities match activity demands.

Kielhofner also suggested that people develop a unique pattern of interests, which accumulates through experience. People make choices about occupation over time, according to their preferences, and these often develop into a pattern of choices. He suggested that the patterns of interests that people develop are “usually paralleled by a routine in which their interests are at least partially indulged” (p. 44). The concept of a pattern of interests forms a link to the next component of MOHO: habituation.

Habituation

MOHO proposes that the things that people do in their daily lives become routinized and taken for granted through a process of habituation. Habituation is defined as “an internalized readiness to exhibit consistent patterns of behaviour guided by habits and roles and fitted to the characteristics of routine temporal, physical and social environments” (Kielhofner, 2008, p. 52). It serves the purpose of reducing the degree to which decisions about action have to be made consciously.

Habituation is assumed to require cooperation with the environment in order to support people’s routine action, in that, a degree of environmental stability is necessary for the development of habitual occupational performance. Using an image with broader application than to humans alone, Kielhofner stated, “The regularity in habituated behaviour depends on the reliability of habitats” (p. 52). The stability of habits relies on temporal patterns (e.g. daily, weekly, annual cycles), a stable social order and a consistency of physical places that an individual might inhabit.

Kielhofner (2008) presented two components of habituation. These are habits and internalized roles. Habits are patterns of behaviour that have a level of consistency about them and are often performed automatically. That is, the decision to engage in them and, often, to carry them out requires little thought. In addition, once commenced, habits require low levels of conscious effort, which frees up thought for other things while undertaking habitual activity. Habits rely on a familiarity with the environment that allows people to internalize rules for behaviour. When these rules have not been developed, often because the environment (or aspects of it) is novel, people are unable to respond in habitual ways.

The advantage of habits is both the freeing up of conscious thought for other things and, often, efficiency of response. For example, where habits have developed from action that has been modified over time within the same context, they can result in efficient and effective behavioural responses to that environment. Expertise in a particular area may be a result of this process, in that, experts often appear to know what to do and are able to act with little apparent thought (respond habitually). It is only when something about the situation presents itself as novel that experts seem to need to engage in problem solving and deciding the best course of action.

Kielhofner (2008) identified three types of habits. First, the term habits of occupational performance refers to how people habitually perform routine activities. People develop habitual ways of doing daily activities such as dressing and bathing, as well as other frequently performed activities such as cooking, eating, and working. Second, people develop habits of routine. This refers to how people use time and space and how these ways become routinized. These routines can apply to different periods of time. For example, they could be daily (or within the day), weekly such as routines related to activities such as work or school (i.e. when you are working/studying and when you are having time off), seasonal (e.g. farmers), annual and so forth. Third, people develop habits of style. This refers to one’s typical way of being in the world. Some examples that Kielhofner gave were whether a person typically attended to details or preferred to look at the broader picture, and whether they were prompt or procrastinating, quiet or talkative and trusting or cautious.

Over the course of the lifespan, habits can remain relatively stable or change. For example, some habits are considered socially acceptable at certain ages but not others. For an individual, some habits might serve an adaptive purpose at some times or in some circumstances and might gain an unwanted response in other situations. Some habits are the result of socialization and others are more related to the individual’s particular experiences and ways of living.

The second component of habituation is internalized roles. The social system surrounding a person influences the roles that the person might desire, choose, be expected to fulfil or be prevented from obtaining. Roles powerfully influence the way human occupation is performed. As Kielhofner (2008) suggested, the process of internalizing roles “means taking on an identity, an outlook, and actions that belong to that role. Consequently, an internalized role is the incorporation of a socially and/or personally defined status and a related cluster of attitudes and actions” (p. 59).

In MOHO, an important aspect of internalized roles is role identification. Roles contribute to a person’s self-identity. As Kielhofner (2008) stated, “identifying with any role means internalizing both what attributes society assigns to the role and one’s personal interpretation of that role” (p. 60). When people take on roles they gain feedback about both their own perceptions of how well they have fulfilled those roles and the perceptions of others in society. All of this feedback contributes to how people think and feel about themselves. Internalized roles also provide people with “an internalised script” (Kielhofner, 2008, p. 60) that guides their behaviour by providing an understanding of the expectations of others and of themselves.

Kielhofner (2008) also proposed that roles organize occupations by: (1) influencing the style and content of people’s actions; (2) shaping what people do; and (3) giving organization to time and space (e.g. by being in a certain role at a certain time in a certain place). Roles change over time, as people grow and mature, change their interests and plans, and as the context in which they live changes or their abilities change. As roles change, people’s occupational engagement and performance will also change. An individual’s capacity for performance and his or her experience of performance contribute to his or her ability to carry out roles and are described in the following section.

Performance capacity and the lived body

In this third component of MOHO, the focus moves from the volition to act and the habits and roles that support and surround action to the action itself. In MOHO, action, referred to as performance, is discussed in terms of the capacity for performance and the embodied experience of performance. The phenomenological term “the lived body” is used to label this embodied experience.

Performance capacity refers to “the ability to do things” (Kielhofner, 2008, p. 68) and is conceptualized as having objective and subjective components. Objective components of performance capacity include the capacities of body systems such as musculoskeletal, neurological and cardiopulmonary systems, amongst others, as well as cognitive abilities. Kielhofner (2008) identified that other occupational therapy conceptual practice models detail performance capacities in greater depth by providing “specific explanations of physical and mental components and their contribution to performance” (p. 18). Examples include motor control models, cognitive approaches, etc. In contrast, MOHO provides little detail about these objective performance components, but emphasizes that performance capacity has both objective and subjective aspects.

Subjective experience refers to how the individual experiences performance and is understood to shape that experience. Kielhofner (2008) viewed attention to subjective experience as a neglected aspect of performance in occupational therapy, claiming that “focusing on the subjective aspect of performance capacity is complementary to the traditional objective approach” (p. 69). He referred to objective approaches as viewing performance capacity “from the outside” and subjective experience of performance capacity as viewed from the “inside” (p. 69). However, he proposed that, when occupational therapists ask people about their subjective experiences, they are actually doing so in order to build “an objective picture of performance capacity” (p. 69).

In the fourth edition of MOHO, the concept of subjective aspects of performance capacity is mainly discussed in contrast to objective performance components without providing much detail about what subjective aspects of performance includes. Therefore, it is unclear whether the subjective experience of performance capacity is conceptualized as separate to or a part of the other concept related to this component of human occupation, “the lived body”.

The term lived body comes from phenomenology (a discipline of philosophy) and refers to the body as it is lived or experienced. It has been used in occupational therapy to refer to the embodied experience of performance (Mattingly & Fleming, 1994), that is, the fact that we live and move in a particular body, which shapes our experience of action. Subjective performance components might be conceptualized as part of the lived body. In explaining the concept of the lived body, Kielhofner (2008) made reference to the philosopher Merleau-Ponty: “unlike the objective approach which describes performance from a detached, objective perspective, he [Merleau-Ponty] emphasized a phenomenological approach that considered subjective experience as fundamental to understanding human perception, cognition, and action” (p. 70).

“The lived body” emphasizes that the body is the vehicle through which life is lived and performance is experienced. Therefore, the capacity for and carrying out of performance is dependent on each individual’s particular body. Phenomenology emphasizes that, in ordinary experience, the body forms the invisible background against which people attend to the occupations they are performing. The focus of attention is on the occupation rather than the body’s participation in it. When people acquire impairments or have changes to their capacities, the body often comes to the foreground and can become the focus of attention.

In explaining the implications of the lived body for understanding human occupation, Kielhofner (2008) stated, “the lived body concept underscores two fundamental ideas” (p. 70). These are that (1) from the lived body perspective, there is a unity of mind and body (in that we experience our body and mind in an integrated way, as part of our bodies) and that (2) subjective experience of performance is fundamental to performance (we experience our own action as a part of us rather than as something objective and separate). Kielhofner argued that insufficient attention has been paid in occupational therapy to the lived experience of human occupation compared to its objective components.