Applied behaviour analysis is an approach to behaviour modification that treats a problematic or unwanted behaviour itself as the direct target for change, rather than treating that behaviour as a surface symptom pointing toward some separate, deeper underlying cause that needs to be uncovered first. Its core method is to carefully identify exactly what's currently reinforcing the behaviour, what consequence is making the behaviour more likely to keep happening, and then systematically change those reinforcing consequences to change the behaviour's future frequency.
Every persistent behaviour is being reinforced by something, even if it's not obvious
Applied behaviour analysis starts from the basic behavioural premise that a behaviour persisting over time is generally being reinforced by some specific consequence that follows it, even when that reinforcing consequence isn't immediately obvious to an outside observer, or even to the person exhibiting the behaviour themselves. A behaviour that seems, on its surface, to serve no clear purpose might actually be reinforced by attention it draws, by escape from an unwanted task or situation, or simply by the sensory experience the behaviour itself produces — identifying which of these is actually operating in a specific case is the analytical first step applied behaviour analysis relies on before any intervention.
Changing the reinforcement changes the behaviour, without needing a separate diagnosis first
Once the specific reinforcing consequence maintaining a behaviour has been identified through careful, systematic observation, applied behaviour analysis intervenes by changing that consequence directly, removing the reinforcement the unwanted behaviour was receiving, or providing an equivalent reinforcement for an alternative, more desirable behaviour instead. This behaviour-first approach is precisely what distinguishes applied behaviour analysis from therapeutic approaches that instead focus primarily on uncovering and treating some presumed underlying psychological cause; the behavioural approach treats systematically and directly changing the behaviour's environmental consequences as the actual, sufficient intervention.
What we're still unsure about
Applied behaviour analysis's core methodology, and its extensive track record of measurable effectiveness for particular target behaviours in particular settings, are well documented across decades of behavioural research and clinical application. What remains more genuinely a matter of debate, both within and outside the field, is how broadly this behaviour-first approach should be applied relative to therapeutic approaches that place more emphasis on a person's internal emotional or cognitive experience, and different clinicians and researchers continue to hold genuinely differing views on where applied behaviour analysis is the right primary tool versus where it works best only alongside other therapeutic approaches, rather than there being one settled consensus on that broader question.
This sits inside Behaviour Modification & Applied Behaviour Analysis, one of seven topics in Behavioral Psychology, one of four domains in Psychology, one of seventeen subjects the app can quiz you on.