Fagen, A, Acharya, N and Kaufman, G E (2014), Positive Reinforcement Training for a Trunk Wash in Nepal’s Working Elephants: Demonstrating Alternatives to Traditional Elephant Training Techniques. Journal of Applied Animal Welfare Science, 17(2): 83–97

The study by Ariel Fagen, Narayan Acharya, and Gretchen E. Kaufman focused on evaluating the effectiveness of Secondary Positive Reinforcement (SPR) training methods for free-contact elephants in Nepal, specifically for voluntarily participating in a trunk wash for tuberculosis testing.

Psychology Being Investigated

  1. Operant Conditioning – The study explores operant conditioning, a learning process where behaviours are controlled by their consequences. In SPR, desirable behaviours are reinforced with rewards (positive reinforcement), increasing the likelihood of these behaviours being repeated.
  2. Positive Reinforcement – SPR involves introducing a positive stimulus (a reward) after a desired behaviour is performed, strengthening that behaviour. This technique contrasts with traditional methods that often use negative reinforcement or punishment.
  3. Animal Learning and Behavior Modification – The study delves into how learning theories apply to animals, particularly elephants. It examines how behavioural modification techniques can be adapted to animal training, moving away from aversive methods towards more welfare-oriented approaches.
  4. Impact of Training Methods on Animal Welfare – A significant aspect of the psychology being investigated is the impact of training methods on the psychological well-being of animals. The study implicitly explores how humane training methods like SPR can positively affect animals’ mental health and welfare, reducing stress and improving cooperation.
  5. Understanding Animal Behavior and Cognition – The study also contributes to understanding the cognitive capabilities of elephants, including their ability to learn, remember, and respond to training cues. It sheds light on the cognitive processes underlying learning in animals and how they can be leveraged in training.

Background to the Study

The study by Ariel Fagen, Narayan Acharya, and Gretchen E. Kaufman is set against the backdrop of traditional elephant training methods in Nepal, which heavily rely on punishment and aversion techniques. Amidst a global shift towards more humane animal training approaches, particularly in zoos and conservation areas, this study focuses on introducing and assessing the effectiveness of Secondary Positive Reinforcement (SPR) training. This humane alternative, which rewards desired behaviours to encourage repetition, was applied to train captive elephants to voluntarily participate in a trunk wash for tuberculosis testing. The study’s context highlights the increasing emphasis on animal welfare and the psychological impact of training methods, aiming to demonstrate a more ethical approach to managing captive elephants’ health and well-being.

Aims of the Study

The study aimed to assess whether SPR techniques could be effective to train free-contact elephants in Nepal. This was particularly focused on training them to voluntarily participate in a trunk wash, a procedure necessary for tuberculosis testing.

Procedure and Methodology

  • Sample – The study involved five female elephants, four juveniles and one adult, housed in the same stable in Nepal. These elephants were traditionally trained and had no previous exposure to SPR training​​.
  • Training Methodology – The SPR technique involved using a short whistle blow as the secondary reinforcer and chopped bananas as the primary reinforcer. Training occurred in morning and afternoon sessions while the elephants were chained in their stalls. The presence of the elephants’ mahouts was required for safety, but they were instructed not to interact with the elephants during training sessions.
  • Behavioural Tasks – The elephants were trained in five basic behavioural tasks:
    • Trunk here (placing the trunk in the trainer’s hand),
    • Trunk up (lifting the trunk upward),
    • Bucket (placing the trunk in a bucket),
    • Blow (exhaling strongly through the trunk),
    • Steady (holding the trunk still in the requested position).
  • Training Process – The process involved initially teaching the elephants the bridge between the primary and secondary reinforcers, followed by training in the basic tasks using capture, lure, and shaping techniques. The elephants were then trained to perform these tasks in sequence (behavioural chaining), culminating in the full trunk wash sequence.
  • Desensitisation and Counterconditioning – This was used to introduce the syringe and sample fluid, gradually acclimating the elephants to these elements of the trunk wash.
  • Data Collection – Training sessions were timed, and the number of cues given for each behaviour was tallied. Performance tests were administered approximately every five sessions to assess the elephants’ proficiency in the trained behaviours.


  • Four juvenile elephants successfully learned the trunk wash within 35 sessions or fewer. The mean success rate improved from 39.0% to 89.3% following training.
  • The total training time varied among elephants, ranging from 257 to 451 minutes.
  • The relative difficulty of tasks was assessed based on the number of offers necessary to achieve a passing score​​.


  • SPR was found to be a feasible and efficient training method for juvenile elephants.
  • The study demonstrated that elephants could be trained voluntarily without resorting to traditional punishment-based methods.
  • SPR training could be beneficial in various captive management programs globally​​.


  • Standardised Training Procedures – The study utilized standardised training procedures across all subjects. Each elephant was trained using the same basic behavioural tasks (e.g., ‘Trunk here’, ‘Trunk up’, ‘Bucket’, ‘Blow’, ‘Steady’) and the same sequence of training steps. This standardisation enhances the internal validity of the study by ensuring that any observed differences in learning and performance were due to the elephants’ individual differences rather than variations in training methods.
  • Repeatability of Results – The training methodology employed in the study is replicable, allowing for repeated studies to verify results. The clear documentation of the training procedures, the use of objective measures, and the detailed description of the behavioural tasks make it possible for other researchers to replicate the study. This repeatability is crucial for validating the findings and contributes to the overall reliability of the research.
  • Ecological Validity – The study was conducted in a natural setting where the elephants were already living and being cared for. This means the training occurred in the elephants’ regular environment, rather than in a contrived laboratory setting. Such a setting enhances the ecological validity of the study, as the behaviours and responses of the elephants are more likely to reflect how they would react in real-world situations.


  • Limited Sample Size and Diversity – The study involved only five elephants, all of whom were female and predominantly juveniles. This limited sample size and lack of diversity in age and sex may reduce the generalizability of the findings. The results might not represent male elephants, older elephants, or those with different backgrounds or training histories.
  • Subjective Assessment Criteria – The criteria for judging the success of the trained behaviours were subjectively determined by the trainer. While performance tests were used to assess proficiency, the determination of whether a behaviour was of sufficient quality for the trunk wash was based on the trainer’s judgment. This subjective assessment could introduce bias and affect the validity of the results.
  • Potential Environmental and External Influences – The training environment included potential distractions such as the presence of tourists, other animals, and proximity to meal times. These factors could have influenced the elephants’ performance and learning rate, potentially affecting the validity of the study’s results. Additionally, the study did not control for these external variables, which might have impacted on the training effectiveness and the elephants’ responses, also affecting the validity of the results.