At a basic level, we are both mammals. We are warm-blooded, breathe air and give birth to live offspring.
However, our biological connection stretches far beyond basic biology. We are both intelligent and social animals, although we evolved this lifestyles in very different ways.
For starters, humans and many marine mammals live in tight-knit groups, remaining part of the family unit for their entire lives. In fact, social bonds may even be stronger in some dolphins species than in humans. Within these social groups, cetaceans can spend several years rearing their young, further strengthening family ties. Family members other than the parents can also assist in raising young. Playing is also an important part of both human and cetacean societies, both to practice skills for the future and maintain relationships. At the other end of life, whales appear to share our tendency to mourn the dead, staying with a group member long after they have passed.
In addition to their social lives, we both share complex and developed emotional lives. Whales and dolphins can likely be joyful, curious, angry, and grieving- just like us.
Due to this social way of life, we both have complex and sophisticated systems of communication, primarily through vocalisations. Moreover, we have yet to discover the full complexity of cetacean communication. Body language is also important to both groups, with physical contact a crucial way of affirming bonds.
Finally, we regard both humans and whales as highly intelligent species, capable of solving problems and adapting to any situation. However, since we live in such different worlds (humans on land and whales underwater), it is impossible to determine the true intelligence of whales and dolphins. We probably have much to learn.
In short, we should both and celebrate the differences and similarities that humans share with whales.