My colleague’s argument that interventions based on behavioral theory do not work is flawed. He equates “behavioral interventions” with “theoretical basis”, and therefore claims theory-based interventions do not work because behavioral interventions have not been shown to work. As I argued in my opening statement, it is important to make a clear distinction between interventions based on behavioral theory, those merely ‘inspired’ by behavioral theory, and those that do not encompass theory at all. My colleague fails to make this distinction, and ignores evidence demonstrating the efficacy, and effectiveness, of interventions demonstrably based on behavioral theory in real world contexts. A further problem with his argument is to cite evidence of population-level non-change in rates of non-communicable disease and health-related behavior as evidence that behavioral theory does not work in the real world. It’s a poor argument without foundation. This is typified in his argument that the 25-year “falling or flatlining” of physical activity participation is somehow illustrative of a failure of behavioral interventions. This inference, which is speculative, is based on survey data on sport in which no intervention is identified. To make matters worse, this argument also infers that population-level changes in sport participation should reflect a desirable health-related outcome, a position he himself has argued against . He also argues that considerable flux occurs in individuals’ behavior over time while a “steady state” is generally observed, suggesting that behavioral interventions capture this “volatility” rather than actual change. Yet, no evidence on theory-based behavioral interventions is offered to illustrate this point – the “Get Active: Get Healthy” campaign he cites, best way to dry cannabis a sport-oriented intervention without basis in behavioral theory, provides no relevant data to verify this claim.
Researchers designing trials of behavioral interventions are all too aware of the issue of time-dependent variability in health behaviors, and include appropriate covariates in their analyses to demonstrate intervention effectiveness is in spite of, not because of, population-level variation in behavior. However, better evidence than that cited by my colleague supports his contention that population level change in health behaviors has not been achieved. Behavioral scientists’ should shoulder some of the blame for this failure by not advocating better implementation of effective interventions, but so too should all involved in the ‘chain of development’ of behavioral intervention from basic research to implementation. My colleague also argues that: “Behavioral theory can provide neither the explanation…on the wider causal systems that underpin… behaviors such as low physical activity and poor diet”. This argument is incorrect, my colleague probably equates all behavioral theories as theories of individual behavior, which reflects a deficient knowledge of behavioral theory. Many behavioral theories incorporate socio-demographic, structural, and group-level variables as determinants of behavior, and propose how they interact with psychological determinants. Similarly, my colleague argues that: “Undoubtedly, it is the focus on the individual rather than the population that undermines the real-world effectiveness of behavioral theory.” I agree that a simple causal narrative, such as a sole focus on individual behavior change , will not be effective in reversing population-level incidence of non-communicable disease. However, this is not a failure of behavioral theory per se; many theories encompass individual, structural, and ecological determinants of behavior. Rather, it points to a need to incorporate interventions based on behavioral theory into policy and practice through advances in implementation science.
Finally, my colleague suggests that theory-based behavioral interventions target only the motivated. This is not a new argument, intervention designers have been aware of this problem for years, and it is a problem that pervades most interventions, regardless of their theoretical basis. However, this is not the case for all interventions, and some of the most effective interventions work in changing behavior independent of motivation and in ‘real world’ contexts without the strict controls associated with laboratory research. In conclusion, I commend my colleague for identifying the need for more effectiveness trials and translation efforts for theory-based behavioral interventions. However, his arguments against the effectiveness of behavioral theory in ‘real world’ contexts reflect an acute lack of understanding of behavioral theory, are based on incorrect inferences regarding behavioral theory, fall back on emotive language in an attempt to persuade, make no practical suggestions on the way forward for behavior change, and, as a consequence, should be summarily dismissed.The arguments for behavioral theory barely warrant rebuttal. The volume of evidence presented for effectiveness demonstrates that those who receive behavioral theory interventions show changes in behavior compared to those who do not. This is evidence of efficacy, not effectiveness, a distinction not well understood in the literature. The appeal to implementation science is an attempt to extend controlled efficacy trial environments into implementation, focusing, for example, on maximising intervention fidelity to achieve an illusion of effectiveness that is impractical, uneconomic and largely futile for achieving behavior change at scale. Finally, the litany of under-funded and unsustained interventions, which are presented as a result of poor communication by behavioral theorists and poor understanding by policy makers, suggests behavioral theorists are collaborating in their own victim narrative.
Investment in implementing interventions has not been sustained because interventions have not been shown to be effective. But worst, because “implementation science” has sought to extend the controls of phase II and III efficacy and comparative efficacy trials into implementation, opportunities have been squandered to upgrade evidence by conducting genuine phase IV observational, non-interventional effectiveness trials in naturalistic settings.Behaviors change regularly and often. In England, circa 18 million adults change their sport participation each year, yet population sport participation levels have remained stable for quarter of a century. Shifting the curve of population behaviors requires an entirely different approach than changing individual behavior. Successes in the former include the use of seatbelts, and reductions in drink-driving and in smoking in public spaces, but they result from legislative mandating, not effective behavioral theory interventions. Since the 1960s in England, tobacco advertising, and then tobacco sponsorship, was regulated, restricted and then banned, followed by increasing restrictions and then a ban on smoking in public spaces, with a ban in cars and rented social housing now also being considered. Latterly, warnings then graphic images of increasing severity and size have been required on tobacco products, which now cover the whole packaging. Legislation has regulated messages and mandated behaviors, including mandated engagement with efficacious fear appeal interventions to ensure intervention fidelity and deliver effectiveness that would not otherwise be possible. Now, 50 years on, society no longer supports the social practice of smoking, and not only is the tobacco industry not permitted to reinforce smoking as a desirable behavior, it is required to undermine it. The role of behavioral theory in this process has been minimal; success is attributable to understanding the meanings attached to smoking as a social practice, the ways in which it is reinforced, and to addressing social and economic causation through incremental legislative mandating that disrupts the social practice of smoking.The academic practice of the development of behavioral theory shows the signs of paradigmatic science. Theorists become self-reinforcing and self-referential devotees, advocates for theory rather than outcomes. Empirical deficiencies are attributed to imprecise specification or poor implementation, prompting calls for more meticulous use and more controlled implementation, or for tweaks at the margins of theory. Social ecological approaches, which co-opt social perspectives to support existing individualistic behavioral solutions, weed drying rack rather than to interrogate and understand social and economic causation, are an example of the latter. Kuhn suggests these circumstances create the structure for scientific revolutions, in which empirical deficiencies can no longer be explained away at the margins or blamed on methods, and the old paradigm is displaced in favour of a new approach. I propose that new approach should be a social practice framework that deploys legislative mandating as a tool to disrupt social practices, underpinned by understanding of social and economic causation.
This should displace the current dominant individualistic behavioral paradigm that provides solutions that are not connected to causes. It’s time to burn down the house: the time for revolution is now!Although the current debate has showcased our different perspectives, it has also highlighted points of agreement. We both agree that interventions based on behavioral theory are efficacious in changing health-related behaviors. We also agree that there are problems with current evidence for the effectiveness of behavioral interventions, but we disagree on the nature and extent of these problems and their implications for drawing conclusions about the ‘real world’ effectiveness of behavioral theory. Beyond this, we also disagree on the implications of the evidence base as it stands for advancing effective, long-term solutions to the increasing prevalence of non-communicable diseases.While evidence for real world effectiveness of interventions based on behavioral theory applied in real world contexts is limited, it is not absent. Good examples of theory-based interventions that have demonstrable real-world effectiveness in changing behavior exist . Behavioral interventions offer a range of strategies that, if appropriately implemented, can and will make lasting changes in behavior at the population level. However, I recognize the need to develop the evidence base of effective large-scale behavioral interventions that can be embedded within existing networks, and are sensitive to the social and cultural norms of the target population. The interventions need to be sustainable through, for example, their incorporation into routine care or standard practice.Those developing interventions need to actively engage and lobby policymakers and governments to invest in interventions with demonstrated effectiveness and include them as core components of existing services. Behavioral interventions should be an integral part of a co-ordinated set of strategies that also includes policy change and legislation targeting change in specific behaviors at the population-level.Fundamental change is required: a paradigm shift to focus on social practice rather than individual behavior. Evidence that behavioral theory interventions are genuinely effective among those offered them, rather than simply efficacious among those receiving them, is all but absent, and absence of evidence is evidence of absence. The effectiveness gap is one of engagement that cannot be bridged by persuasion, rather mandating is required, either through legislation, or through interventions with mandatory engagement, such as point of choice information. Nonetheless, there is a role for behavioral theory: firstly, in providing efficacious support for individuals wishing to change; secondly, as a minor dimension of a social practice approach, which places historic and contemporary social and economic forces that lead to the existence of social practices, and that sustain them, at the centre, rather than the contemporary behaviors of individuals. Social practices can be disrupted over time through the incremental interplay of legislative mandating, and social change that creates the conditions for legislation. However, the circumstances and pace of disruption are rooted in understanding social and economic causation, and how this underpins the distribution and acceptance of behaviors in a population, not in aggregative attempts to effect individual behavior change.In commercial agriculture, weeds threaten effective crop production by competing with agricultural crops for resources , depleting soil nutrients, and interfering with agricultural operations, such as harvesting. In addition, weeds may serve as hosts for pests and pathogens, disrupting crop production. In 2017, over 400 types of pesticides were used in the United States, amounting to over one billion pounds . Despite the prevalence of pesticides, weed management for specialty crops still faces significant issues due to the increasing number of herbicide resistant weeds. In addition, weed management in high-value specialty crops encounters a unique challenge: the hesitancy of herbicide registrants to specify specialty crops on herbicide labels due to financial liabilities . Due to concerns associated with herbicide application, such as increased herbicide resistance and a growing demand for organic production, manual hand weeding has become an essential strategy in weed management. However, the expenses and difficulties of hand weeding make it one of the greatest weed management constraints that California growers face. The labor rates are impacted by recent California state legislation that increased the minimum wage to $15.00 per hour in 2022 and $16.00 in 2024 . Moreover, as a result of California Assembly Bill 1066 , the overtime threshold, defined as the hours of work required before employees receive overtime benefits, in the agricultural industry has decreased to 40-h weeks and 8-h workdays in 2022 . Because of these increased labor protections, on-farm labor has increased in cost, and for organic crops and high-density planting, hand weeding can cost more than $280 per acre for romaine hearts in the Central Coast .