In positive psychology, flow, also known as the zone, is the mental state of operation in which a person performing an activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity. In essence, flow is characterized by complete absorption in what one does. Named by Mihály Csíkszentmihályi, the concept has been widely referenced across a variety of fields (and has an especially big recognition in occupational therapy), though has existed for thousands of years under other guises, notably in some Eastern religions. Achieving flow is often colloquially referred to as being in the zone.
According to Csikszentmihályi, flow is completely focused motivation. It is a single-minded immersion and represents perhaps the ultimate experience in harnessing the emotions in the service of performing and learning. In flow, the emotions are not just contained and channeled, but positive, energized, and aligned with the task at hand. The hallmark of flow is a feeling of spontaneous joy, even rapture, while performing a task, although flow is also described (below) as a deep focus on nothing but the activity – not even oneself or one’s emotions.
Flow has many of the same characteristics as (the positive aspects of) hyperfocus. However, hyperfocus is not always described in a positive light. Some examples include spending “too much” time playing video games or getting side-tracked and pleasurably absorbed by one aspect of an assignment or task to the detriment of the overall assignment. In some cases, hyperfocus can “capture” a person, perhaps causing them to appear unfocused or to start several projects, but complete few.
Jeanne Nakamura and Csíkszentmihályi identify the following six factors as encompassing an experience of flow.
- Intense and focused concentration on the present moment
- Merging of action and awareness
- A loss of reflective self-consciousness
- A sense of personal control or agency over the situation or activity
- A distortion of temporal experience, one’s subjective experience of time is altered
- Experience of the activity as intrinsically rewarding, also referred to as autotelic experience
Those aspects can appear independently of each other, but only in combination do they constitute a so-called flow experience. Additionally, psychology expert, Kendra Cherry, has mentioned three other components that Csíkszentmihályi lists as being a part of the flow experience:
- “Immediate feedback” 
- Feeling that you have the potential to succeed
- Feeling so engrossed in the experience, that other needs become negligible
Just as with the conditions listed above, these conditions can be independent of one another.
A flow state can be entered while performing any activity, although it is most likely to occur when one is wholeheartedly performing a task or activity for intrinsic purposes. Passive activities like taking a bath or even watching TV usually do not elicit flow experiences as individuals have to actively do something to enter a flow state. While the activities that induce flow may vary and be multifaceted, Csikszentmihályi asserts that the experience of flow is similar despite the activity.
Flow theory postulates three conditions that have to be met to achieve a flow state:
- One must be involved in an activity with a clear set of goals and progress. This adds direction and structure to the task.
- The task at hand must have clear and immediate feedback. This helps the person negotiate any changing demands and allows them to adjust their performance to maintain the flow state.
- One must have a good balance between the perceived challenges of the task at hand and their own perceived skills. One must have confidence in one’s ability to complete the task at hand.
However, it was argued that the antecedent factors of flow are interrelated, as a perceived balance between challenges and skills requires that one knows what he or she has to do (clear goals) and how successful he or she is in doing it (immediate feedback). Thus, a perceived fit of skills and task demands can be identified as the central precondition of flow experiences.
In 1987, Massimini, Csíkszentmihályi and Carli published the 8-channel model of flow shown here. Antonella Delle Fave, who worked with Fausto Massimini at the University of Milan, now calls this graph the Experience Fluctuation Model. The Experience Fluctuation Model depicts the channels of experience that result from different levels of perceived challenges and perceived skills. This graph illustrates one further aspect of flow: it is more likely to occur when the activity at hand is a higher-than-average challenge (above the center point) and the individual has above-average skills (to the right of the center point). The center of this graph (where the sectors meet) represents one’s average levels of challenge and skill across all activities an individual performs during their daily life. The further from the center an experience is, the greater the intensity of that state of being (whether it is flow or anxiety or boredom or relaxation).
Several problems of this model have been discussed in literature. One is, that it does not ensure a perceived balance between challenges and skills which is supposed to be the central precondition of flow experiences. Individuals with a low average level of skills and a high average level of challenges (or the other way round) do not necessarily experience a fit between skills and challenges when both are above their individual average. In addition, one study found that low challenge situations which were surpassed by skill were associated with enjoyment, relaxation, and happiness, which, they claim, is contrary to flow theory.
Schaffer (2013) proposed 7 flow conditions:
- Knowing what to do
- Knowing how to do it
- Knowing how well you are doing
- Knowing where to go (if navigation is involved)
- High perceived challenges
- High perceived skills
- Freedom from distractions
Schaffer also published a measure, the Flow Condition Questionnaire (FCQ), to measure each of these 7 flow conditions for any given task or activity.