Is Dolphin-Assisted Therapy Actually Therapy?

A scholarly review of available data strongly suggests it's not.

Posted Jan 27, 2021

"I would need rock solid evidence that dolphins can transform an isolated child with autism to a skilled communicator, or that a couple of hours of dolphin play could add fifteen points to the IQ of a girl with Down's Syndrome, or that dolphin electric fields could jolt the middle age depressive out of a debilitating funk. Unfortunately, that evidence is about as solid as, err....the support for back-to-the-womb regression therapy." —Hal Herzog, "Does Dolphin Therapy Work?"

I recently read a thorough review about the effectiveness of Dolphin Assisted Therapy (DAT) by Lori Marino and the late Scott Lilienfeld, and was greatly impressed with the detailed analyses these experts conducted on a large number of studies on DAT. Marino and Lilienfeld concluded the DAT literature continues to be marked by several weaknesses in both internal and construct validity that preclude confident inferences regarding the intervention's efficacy and there is still insufficient evidence that DAT has therapeutic value.

I'm pleased to offer this guest essay by Lori Marino about this most important study. Here's what she had to say:

Dolphin Assisted Therapy (DAT) is a worldwide popular treatment for mental and physical disorders in which a patient swims with or interacts with a captive dolphin with the expectation that contact with the dolphin has therapeutic effects.1 DAT was introduced in the 1970s and later renounced by anthropologist Betsy Smith. These facilities persist, targeting people with autism spectrum disorder and other developmental conditions but claiming success for everything from depression to skin conditions. And the proponents of DAT appeal to a range of “explanations” to justify their exorbitant fees. These include the “healing effects” of dolphin echolocation to biophilia to a purported deep emotional connection between the dolphins and the patients. Moreover, many psychology and therapy organizations tout its effectiveness and promote DAT alongside empirically-based treatments.

DAT facilities continue to be ubiquitous in the United States, Europe, Mexico, the Middle East, and South America despite the fact that the International Association of Human-Animal Interaction Organizations (IAHAIO), which oversees all animal-assisted therapies, disallows the use of wild animals, such as dolphins, in these practices. Still, the DAT industry flourishes on the basis of testimonials and the hopes of parents and patients desperate for a treatment or cure for what ails them.

What is the truth behind DAT? Is it actually therapy? The late Scott Lilienfeld and I have examined this question for the past 22 years by analyzing all of the existing peer-reviewed papers claiming success, starting in 1998 and then again in 2007. Both reviews showed that the existing DAT literature at the time was based on flawed data and flawed conclusions. Our latest, the third in this series in the Journal of Clinical Psychology asks the question, "Third time’s the charm of three strikes you’re out? An updated review of the efficacy of dolphin assisted therapy for autism and development disabilities." As in our earlier papers, we analyzed the construct and internal validity of DAT and found, once again, that despite some improvements in methodology, there is, to date, no concrete evidence that DAT is an effective form of therapy for any disorder.2,3,4 The third time was not the charm. We showed that most “improvements” could not rule out the placebo and other nonspecific effects (construct validity) or there were too many weaknesses in the way the studies were conducted to draw sound conclusions (internal validity). 

In addition to the lack of therapeutic value, DAT abounds with ethical issues not the least of which is holding dolphins captive and forcing them to interact with people. But also, putting children at risk of injuries, and dashing the hopes of parents who, upon returning home, find there are no long-term positive effects and their child is still sick or disabled.

We concluded in our latest paper, “In short, for both scientific and ethical reasons, we strongly suggest that patient advocacy groups … take special care in recommending and promoting DAT…”. I would add to this admonition that marine mammal veterinarians, scientists, and advocates join together to “take special care” to educate the public about why DAT is harmful to dolphins. Humans and dolphins beware.



1) Numerous references about Dolphin Assisted Therapy can be found here. Contact Dr. Marino ( for a copy of Third time's the charm or three strikes you're out? An updated review of the efficacy of dolphin‐assisted therapy for autism and developmental disabilities.

2) The threats to construct validity we assessed were: placebo effects, that is, improvement due to expectation; novelty effects, that is, improvement due to the energizing influence of a new experience; construct confounding, that is, failure to take into account the fact that the treatment may include more than one active ingredient; demand characteristics, that is, tendency to respond to items in accordance with the perceived hypothesis; and experimenter expectancy effects, that is, tendency for the experimenter to unintentionally bias results in accordance with the hypothesis.

3) The threats to internal validity assessed were: history, that is, the occurrence of one or more life events during the study that could affect the study's outcome variables, such as a major storm during treatment; maturation, that is, changes over time due to natural developmental changes; multiple intervention interference, that is, administration of treatments other than the intended treatment during the course of the study; informant retrospective bias, that is, tendency of informants to selectively recall improvement in accord with expectations or effort justification, that is, the need to rationalize one's investment in the treatment owing to the time, energy, and resources expended; and differential attrition, that is, comparison groups become different because of uneven drop‐out across the groups.

4) A detailed analysis was conducted on these six studies that all met the inclusion criteria of using live dolphins and reporting evidence for treatment efficacy of DAT in a clinical sample using established outcome measures relevant to assessing improvement in the participants. 

Breitenbach, E., Stumpf, E., Fersen, L. V., & Ebert, H. V. (2009). Dolphin‐assisted therapy: Changes in interaction and communication between children with severe disabilities and their caregivers. Anthrozoös, 22, 277–289.

Dilts, R., Trompisch, N., & Bergquist, T. M. (2011). Dolphin‐assisted therapy for children with special needs: A pilot study. Journal of Creativity in Mental Health, 6(1), 56–68.

Griffioen, R., van der Steen, S., Cox, R. F. A., Verheggen, T., & Enders‐Slegers, M. J. (2019). Verbal interactional synchronization between therapist and children with autism spectrum disorder during dolphin assisted therapy: Five case studies. Animals, 9, 716.

Griffioen, R. E., & Enders‐Slegers, M. J. (2014). The effect of dolphin‐assisted therapy on the cognitive and social development of children with Down syndrome. Anthrozoös, 27(4), 569–580.

Kohn, N., & Oerter, R. (2013). Dolphin assisted therapy works: Scientific findings from Eilat and Florida. International Journal of Clinical Psychiatry, 1(1), 1–16.

MdYusof, M. S. B., & Chia, N. K. H. (2012). Dolphin encounter for special children (DESC) program: Effectiveness of dolphin‐assisted therapy for children with autism. International Journal of Special Education, 27(3), 54–67.