C. Fergus Lowe

Behaviour change for better health: nutrition, hygiene and sustainability

As the global population grows there is a clear challenge to address the needs of consumers, without depleting natural resources and whilst helping to improve nutrition and hygiene to reduce the growth of noncommunicable diseases. For fast-moving consumer goods companies, like Unilever, this challenge provides a clear opportunity to reshape its business to a model that decouples growth from a negative impact on natural resources and health. However, this change in the business model also requires a change in consumer behaviour. In acknowledgement of this challenge Unilever organised a symposium entitled ‘Behaviour Change for Better Health: Nutrition, Hygiene and Sustainability’. The intention was to discuss how consumers can be motivated to live a more healthy and sustainable lifestlye in today’s environment. This article summarises the main conclusions of the presentations given at the symposium. Three main topics were discussed. In the first session, key experts discussed how demographic changes – particularly in developing and emerging countries – imply the need for consumer behaviour change. The second session focused on the use of behaviour change theory to design, implement and evaluate interventions, and the potential role of (new or reformulated) products as agents of change. In the final session, key issues were discussed regarding the use of collaborations to increase the impact and reach, and to decrease the costs, of interventions. The symposium highlighted a number of key scientific challenges for Unilever and other parties that have set nutrition, hygiene and sustainability as key priorities. The key challenges include: adapting behaviour change approaches to cultures in developing and emerging economies; designing evidence-based behaviour change interventions, in which products can play a key role as agents of change; and scaling up behaviour change activities in cost-effective ways, which requires a new mindset involving public–private partnerships.

Determinants of operant behaviour in humans: Some differences from animals

The performance of human subjects was investigated on fixed-interval (FI) schedules of reinforcement where responses meeting the schedule requirement produced points, later exchanged for money. For one group (the conventional FI condition) presses on a single response-panel were reinforced according to an FI schedule. For another group the procedure was the same as in the conventional FI condition, except that each response also illuminated a digital clock for 0.5 s. A third group responded on two panels; presses on one panel produced reinforcement on an FI schedule, and presses on the second panel illuminated the digital clock for 0.5 s. Responding in the conventional FI condition varied considerably both within and between subjects and different response measures showed no systematic relationship with FI value. For subjects in the other two groups, the pattern of responding on the clock-illuminating panel was scalloped, showing a pause after reinforcement followed by an accelerated response rate; the post-reinforcement pause was an increasing function, and running rate (calculated after excluding the post-reinforcement pause) was a decreasing function, of the value of the FI schedule. The data were compared with results of animal studies on FI schedules and some of the factors which affect performance on these schedules were analysed.

Verbal Control in Human Operant Behavior

Variables that affect the operant responding of humans were investigated in four experiments. In each case a response-initiated fixed-interval schedule was used in which the fixed-interval was initiated by the first response after reinforcement. Experiment 1 compared performance when responses had two different functions: an observing function as to availability of reinforcement, and a direct reinforcement-producing function. The observing response condition but not the direct reinforcement condition resulted in long postreinforcement pauses, similar to the performance of other species on this schedule. Experiment 2 investigated the effect of prior exposure to a fixed- interval schedule. This resulted in long postreinforcement pauses occurring also in the direct reinforcement condition. In Experiment 3, an external stimulus was provided during the postreinforcement pause. This eliminated the postreinforcement pauses, but pauses reemerged when the stimulus was removed. Experimental conditions were held constant in Experiment 4, but different verbal instructions were given, suggesting that responses either had an observing function or directly produced reinforcement. The observing response instructions but not the direct reinforcement instructions resulted in long postreinforcement pauses. Replies to questionnaires at the end of each experiment suggested that performance depended on a subject’s verbal formulation of the experiment. In every case, those who verbalized the situation as one of temporal regularity produced long postreinforcement pauses, and those who verbalized it as one of response-reinforcement contingency did not pause after reinforcement.

The way to healthy eating for children

There is widespread concern that children consume too few fruit and vegetables and as a result are likely to incur health problems. This paper outlines a series of studies in which an intervention that combines video‐based peer modelling with rewards has been shown to be very effective in enabling children to eat a variety of fruit and vegetables that previously they rejected. These effects have been very substantial and long lasting. The procedure has been used successfully in children’s own homes and, as this paper shows in particular detail, in school settings.

Transfer of function across members of an equivalence class

A child’s presses on response windows behind which stimuli were presented via computer monitor occasionally lit lamps arranged in a column; a present was delivered when all lamps in the column were lit. During the operation of a multiple schedule, the child first learned low rates of pressing in the presence of STAR and high rates in the presence of TREE. Later, in an arbitrary matching task, the child learned to select STAR given wiggly WORM and TREE given BLOCK. When WORM and BLOCK were inserted into the multiple schedule, the low and high rates respectively correlated with STAR and TREE transferred to them. Tests of reflexivity (identity matching) and of symmetry of the arbitrary matching implied that STAR and WORM had become members of one equivalence class, and TREE and BLOCK had become members of another.

Nonverbal behavior correlated with the shaped verbal behavior of children.

Children under 6 years old pressed on response windows behind which stimuli appeared (star or tree). Presses occasionally lit lamps arranged in a column; a present was delivered when all lamps were lit. A random-ratio schedule in the presence of star alternated with a random-interval schedule in the presence of tree. These contingencies usually did not produce respective high and low response rates in the presence of star and tree, but the shaping of verbal behavior (e.g., “press a lot without stopping” or “press and wait”) was sometimes accompanied by corresponding changes in response rate. Verbal shaping was accomplished between schedule components during verbal interactions between the child and a hand-puppet, Garfield the Cat, and used social consequences such as enthusiastic reactions to what the child had said as well as concrete consequences such as delivery of extra presents. Variables that may constrain the shaping of verbal behavior in children seem to include the vocabulary available to the child and the functional properties of that vocabulary; the correlation between rates of pressing and what the child says about them may depend upon such variables.

A home-based intervention to increase physical activity in girls: the Fit ‘n’ Fun Dudes program

There is a strong need to increase physical activity levels and healthy dietary behaviors among children due to rising levels of obesity in many countries worldwide. Following on from previous research on dietary change, the current study evaluated the effects of a home-based physical activity intervention with 32 girls (mean age, 10.6 ± 0.7 years) and their parents. During the 8-day intervention, children were introduced to fictional role models (the “Fit ‘n’ Fun Dudes”) and were given daily pedometer step targets to reach in order to receive small rewards. Pedometer measures were taken from children and parents in the experimental and control groups at baseline, during the intervention, and 12-week follow-up. Children in the experimental group were significantly more active than control children during the intervention on weekdays and weekend days (both p p

After-effects of reinforcement magnitude: Dependence upon context

On a fixed-interval schedule with rat subjects the duration of the post-reinforcement pause was found to be an increasing function of the magnitude of the preceding reinforcer. This relationship was observed when two magnitudes were contrasted closely in time, but not when the subjects were trained on each magnitude until the establishment of stable responding. After the behaviour was stable, the effect of the magnitude of reinforcement re-emerged when 50% of the scheduled reinforcers were omitted. Thus, the positive relationship between the magnitude of reinforcement and the duration of the post-reinforcement pause depended on the context of presentation of a given magnitude.

After-Effects Of Reinforcement Magnitude On Temporally Spaced Responding

Rats were trained on two-component DRL schedules. In testing, a different concentration of liquid reinforcer was used in each session. The main effects were on the interresponse times initiated by reinforced responses. The median duration of these interresponse times and the rate of reinforcement increased as functions of reinforcer concentration. There was a corresponding increase in the efficiency of performance. These effects were attributed to the inhibiting after-effect of the reinforcer, rather than to an increase in the temporal accuracy of performance.

The Aftereffects of Reinforcement Magnitude and Stimulus Intensity

Rats were trained on a fixed-interval schedule where each interval had an equal probability of being terminated by reinforcement or by an auditory stimulus. In testing, the concentration of the milk reinforcer and the intensity of the sound were varied. The durations of both the postreinforcement and the poststimulus pauses were found to be increasing functions of reinforcer magnitude and stimulus intensity, respectively. It is suggested that the effect of changes in the reinforcer magnitude upon the duration of the postreinforcement pause reflects the enhancement or impairment of the discriminative function of the reinforcer in the same way that the discriminative function of any stimulus may be affected by changes in its intensity.