The Chemistry of Man's Best Friend


  • In ancient Egypt people worshiped cats, old European Kings and Nobles were occasionally buried with their pets, and we all at one time have said a few solemn words while standing over the toilet bowl about to flush down a fish. It’s obvious how attached we can become to our pets. We tend to consider them part of the family and I personally know some people with more pictures of their cats on their phone than they have pictures of their children. But why have we given dogs he exclusive title of “man’s best friend”? As an avid dog lover myself, I wanted to find out just what it is that makes them so easy to bond with.Composition of ...Oxytocin - C43H₆₆N12 O12S2
  • Dopamine - C₈H11NO₂
  • Vasopressin - C46H₆₅N15O12S₂

Main Chemicals, Compounds, Components

Oxytocin (C43H₆₆N12 O12S2)

A hormone made of a peptide of nine amino acids and produced in the hypothalamus of the brain. It is produced by all mammals and is the hormone that plays a key role in the formation of trust and affection. Due to this its also know by the nickname the “cuddle hormone”.

Dopamine (C₈H11NO2)

A neurotransmitter, a chemical released by neurons to send messages to nerves and cells, in the brain that is associated with the feeling of joy or happiness.

Chemistry's Role

Oxytocin is the hormone in the body that regulates attraction levels. Biologically it does have the ultimate goal of reproduction but it also is responsible for developing feelings of trust and other bonds like a mother with her offspring. Scientists may also think it is linked to improved facial recognition. Oxytocin is controlled by a positive feedback mechanism. Meaning that release of the hormone in the brain starts a chain reaction that causes more of the hormone to be released.

Dopamine, the neurotransmitter in the brain that causes “happy”, is really the brain is sending out a rewarding feeling. The dopamine is sent into the Basal Ganglia, changing what the brain interprets as a rewarding activity. This is essentially a built in motivator, mostly with the purpose of survival. For example, food may taste good because you body interprets it as pleasurable, hopefully causing you to continue the action that, in this specific case, is necessary to stay alive. THIS TECHNICALLY MEANS THAT YOUR BRAIN THINKS PETTING A DOG IS NECESSARY TO SURVIVAL, WHICH IS THE BEST THING I’VE HEARD ALL DAY!

Vasopressin is a distant cousin to Oxytocin. They are similar in function and are even located on the same chromosome (#20). Vasopressin is specifically set with pair bonding, not just trustworthy feelings or affection that comes from Oxytocin, but a hormone that forms a deep relationship in the brains between animals. In fact, at a molecular level, animals that commit to monogamy (such as penguins or swans both of whom mate for life) have high levels of this hormone.

Background Research

During a recent Japanese study, researchers found that the oxytocin levels in a dog increased after looking at its owner are an elongated period of time. Coincidentally, when the owner looked back and held the gaze, the researchers noticed the same pattern. The researchers tested this also with wolves raised by humans and found very different results. Elongated gazes hardly rose oxytocin levels in either the wolf or human. In conclusion to the experiment, part of the reason we may bond with dog’s so well is because of the intense amounts of Oxytocin they naturally produce, turning them into the large fluffy balls of love we so care for. The results were much more eloquently stated by Steve Chang, an assistant professor of psychology and neurobiology at Yale even though he had little participation in the research process. “What’s unique about this study is that it demonstrates that oxytocin can boost social gaze interaction between two very different species.”


Above sources used to find information on Oxytocin.

Article about a Japanese study trying to find a link between a dog gazing at its owner and a raise in the owner’s Oxytocin levels.

Above sources used to find information on Dopamine.

Above sources used to find information on Vasopressin.