vonHoldt Lab

Evolutionary Genomics and Ecological Epigenomics

Genetics of canine hyper-sociability


My research group, in collaboration with Dr. Monique Udell at Oregon State University, is exploring the molecular mechanisms that influence human-directed hyper-sociability in dogs and wolves. We work extensively with Drs. Elaine Ostrander at NIH/NHGRI, Janet Sinsheimer at UCLA, and Clive Wynne at Arizona State University to integrate genomics and behavioral data gathered from wolves and domestic dogs of any variety, breed, and ancestry. We recently identified mutations in a handful of genes that are associated with increased human-directed social behaviors (vonHoldt et al. 2017, [link]). Interestingly, when many of these genes are deleted in humans, they are known to cause a behavioral syndrome called Williams Beuren Syndrome (WBS). Among a number of central traits, WBS is often identified by extreme friendliness and lacking a fear of strangers. This work has been reported in many media venues (e.g. National Geographic, [link]) as well as on Princeton's homepage [link].

If you want to help keep this research going, there are two ways that you can donate! One is for donating data on your canine companion (see below). The other way is to donate financial support (visit my Benefunder profile, [link]).


Photo Credit: C. Fascenelli 2017

How common is it for canines to carry insertions?

Currently, combined with our past data collection effort from our publication in Science Advances (2017) [link], we are collecting genotype data on 590 canines, which includes 539 dogs and 51 wolves. This effort is to document the number of insertions each individual carries at four loci, with insertions associated with increased human-directed social behavior. Our behavioral measurement is not mututally exclusive to other distinct behaviors, such as aggression, anxiety, shyness, etc.

Below, please find the table that documents updates in our genotyping database, displaying allele and genotype frequencies for each locus.

Cfa6.6 Cfa6.7 Cfa6.66 Cfa6.83
Frequency of insertion in dogs* 63% of 471 dogs 38% of 423 dogs 18% of 437 dogs 16% of 425 dogs
Frequency of dogs that carry 2 insertions 51.9% 20.7% 8% 11.3%
Frequency of dogs that carry 1 insertion 23% 35.1% 20.1% 9.9%
Frequency of dogs that carry 0 insertions 25.1% 43.9% 71.4% 78.8%
Frequency of insertion in 51 wolves 32% 6% 37% 0%
Frequency of insertion in 15 wolves from North America 13.3% 3.3% 30% 0%
Frequency of insertion in 12 wolves from Europe 45.8% 4.2% 37.5% 0%
Frequency of insertion in 14 wolves from Middle East 50% 7.7% 53.8% 0%
Frequency of insertion in 7 wolves from Southwest Asia 21.4% 0% 0% 0%
Frequency of insertion in 3 wolves from China 0% 0% 6.7% 0%

*not each of the 539 dogs are currently genotyped at all four loci

Below is a histogram to show how frequent it is that a dog or wolf carries a total number of insertions across the four loci (hence, eight is the maximum any individual can carry). To find your dog, simply find your dog's total number of mutations along the X-axis (this is provided to your in your dog's report), and the Y-axis will give you the occurance of that value in both dogs and wolves.

Please remember that beahvior is complex! These mutations contribute towards shaping human-directed social behavior; they do not explain the entirety of it. We know that behavior is complex, shaped by both environment and genetics. We know that early life experiences are crucial for shaping adult behaviors, also interacting with the individual's genetic composition. Further, social behavior is not mutually exclusive with many other behavioral presentations (e.g. aggression, anxiety, shy/bold). This assay of four specific mutations does not predict future behavior, nor does it account for past experiences. It is, however, a small glimpse into one of many components that shapes individual differences in behavior.


Documents for Participants

Are you interested in participating in our ongoing canine research of genetics and social behavior?

All dogs are welcome to participate! See the FAQs below for more information on how you can participate. We are continuing with this very exciting opportunity to explore how the same genes involved in WBS may shape behavior of dogs. We have recently expanded our study to also investigate how microbes living in the intestinal tract may influence behavior.


Photo credit: D. Stahler

Here is a collection of documents needed for each dog and owner that wants to donate a genetic sample with demographics and behavioral data. Each document is presented with a short description and a link.

1. Consent form [link]. This is the Princeton University consent form that provides you, the dog owner, information regarding the benefits and risks of participating in this study. This form discloses what each of us are responsible for, and requires your signature/date to participate in this study. Please complete this form and either scan/email to vonholdt@princeton.edu or return a hard copy via the postal service with your swab kit. A hard copy can also be provided in the swab kit if needed. One consent form per family is all that is needed (not one per dog).

2. Demographics and the C-BARQ questionnaire. Please complete this online form that will provide to use demographic and behavioral information [link] for each dog you enroll in the study (estimated time of completion: 10 minutes). Please complete the form once for each dog. If you enroll multiple dogs, the online form needs to be completed once separately for each dog.

3. Sample collection protocols [link]. This document lists two swab protocols, one to collect a cheek/buccal swab from your dog and the other to collect a fresh fecal sample. Both are non-invasive procedures that can be done at home, at your convenience. There is an optional additional collection protocol if you volunteer to donate blood from your dog [link]. This can typically be completed during your dog's annual exam at the vet clinic by a licensed veterinarian. You are welcome to speak with your vet ahead of time to ensure they can comply with this request.

Frequently Asked Questions

Question: Hi! I just saw your ad/flier/website and I would like to how can I participate?
Answer: How exciting to hear that you would like to participate! I like to think of your participation as progressing through three stages.

Stage 1: Basic data collection. This stage consists of completing three forms. The first is the consent form is your acknowledgement that your involvement is voluntary and that you have been made aware of any risk involved. Princeton University (including myself) does not offer reimbursement for any costs accrued. This form will need to be signed and dated before your data and sample can be used in this study. The second is to collect demographic information on each individual dog. This contains standard questions about your dog's birthdate, age, sex, breed, and a few minor health-related questions. The final form is a short 42-question behavioral assessment called the C-BARQ that is to be completed for each individual dog.

All forms can be found on the project's website and will be kept confidential. You can download the forms and email me completed forms (vonholdt@princeton.edu), or you can complete these documents online via the online survey [link] (estimated time of completion: 10 minutes). If you own multiple dogs that you would like to include, please fill out each form separately for each dog! Again, hard copies of the completed forms can be returned to me via email (vonholdt@princeton.edu), and name the scanned file as "LastName_firstName.pdf". The subject line must include "WBS participation" or else my filter may discard it. Alternatively, as a last option, you can use the U.S. Postal Service. My mailing address is: Bridgett vonHoldt, 106A Guyot Hall, Princeton University EEB, Princeton, NJ 08544.

Stage 2: Behavioral data collection. This stage consists of completing the online questionnaire (the C-BARQ; link is above). This document is highly validated and vetted, and also used in several canine behavioral studies. We have published using this questionnaire and find it easier for owners and data collection efforts.

Stage 3: Genetic sample donation. Upon receiving items from both previous stages, if you wish to also donate a non-invasive genetic sample, I will send the collection supplies needed. I must have received all documents and files from Stages 1 and 2 in order to ship you genetic sample collection supplies. This can become incredibly costly and to ensure a high return rate, the previous stages must be first completed. Once completed, you may decide to collect a genetic sample to be included in the study! The collection procedure is simple, involving a non-invasive swab procedure. You can complete this procedure yourself and without a need to visit a vet. The protocol can be found in the above section "Documents for Participants".

Question: My dog is not overly friendly towards or interested in other people, and is a mixed breed. Can I still participate?
Answer: Yes! All dogs are welcome to participate!

Question: I prefer to donate a blood sample from my dog(s). Is that possible?
Answer: Yes! If this is what you prefer, please alert me when you submit your behavioral and demographic data. I will supply you with a blood collection tube and specific instructions for sending in the U.S. postal service. The blood container needs to be in a sealed plastic bag and within a hard container within your shipping box. There is a sampling protocol for blood also found in the Sample collection protocols section.

Question: I live outside of the United States. Can I still participate?
Answer: This is a very hard question to address. Even mailing to supplies to Canada quickly becomes expensive. The best way is to possibly consult with your local vet to inquire if they have cheek/buccal swabs that you pay purchse one and then return that to me via international mail.

Question: Are there results that I can/will receive? How long before I know anything about my dog?
Answer: The reality is that this is a long-term study at an academic institution. My research relies heavily upon obtaining financial support from external agencies (e.g. federal government) or private marketplaces that match philanthropists with research they would like to fund (see my Benefunder profile, [link]!). Also remembering that I have many other duties and services (e.g. educational, committees, outreach) that demand my attention, along with the mentoring of my own students and, of course, publishing. I will work with all resources that I have to provide you a short report on the number and type of gene variants your dog carries. However, these is simply a qualitative report. Behavior is influenced by many molecular and environmental factors. At the moment, the timeline will be hard to estimate. Absolutely consider this ambiguity when deciding if you should participate or not!