Behavioural Theories in Agricultural Extension: A Review of Farmer Decision-Making and Technology Adoption

Agricultural extension is expected to do more than transmit technical information: it must help farmers judge uncertain innovations, develop confidence to act, learn from peers and advisers, and sustain practices under heterogeneous economic and institutional conditions. Behavioural theories have therefore become increasingly prominent in research on farmer decision-making and technology adoption, but they are often applied in isolation and with uneven methodological rigour. This critical narrative review evaluates how major behavioural frameworks have been used to explain and influence agricultural adoption, with emphasis on diffusion of innovations, the theory of planned behaviour, social cognitive and social-learning perspectives, the technology acceptance model and unified technology-acceptance approaches, behavioural-economics concepts, and identity- and norm-based explanations. Literature published mainly from 1985 to 24 June 2026 was examined, while earlier foundational behavioural theory was retained where conceptually necessary. The synthesis indicates that no single theory adequately captures the full adoption process. Diffusion perspectives are strongest for perceived innovation attributes and communication processes; reasoned-action models clarify intentions and perceived control but are vulnerable to an intention-behaviour gap and frequent measurement errors; social-learning approaches explain observation, experimentation and network diffusion; technology-acceptance models are useful for digital tools but can understate infrastructure, trust and actual-use constraints; and behavioural-economics and identity perspectives illuminate timing, uncertainty, loss sensitivity, social meaning and non-financial motivations. Across frameworks, extension is most credible when treated as a behaviour-change system rather than an information-delivery channel. Effective practice requires stage-specific diagnosis of beliefs, capabilities, social influence, uncertainty, trust and structural feasibility, followed by opportunities for trial, feedback and adaptation. Future research should prioritise prospective measurement of actual behaviour, theory-comparative and causal designs, psychometrically sound constructs, network-aware experiments, and integrated models that distinguish behavioural mechanisms from material constraints. Such an approach can make behavioural theory more useful for extension design without reducing farmer choices to psychology alone.