He recognises himself in the mirror, plays hide-and-seek and breaks into fits of giggles when tickled. He is also our closest evolutionary cousin.
A group of world-leading primatologists say this is proof enough that Hiasl, a 26-year-old chimpanzee, deserves to be treated like a human.
In a test case in Austria, campaigners are using a New Zealand precedent to try to cross the "species barrier" and have taken Hiasl's case to court.
If Hiasl is granted human status - and the rights that go with it - it will be a victory for other primate species and unleash a wave of similar cases.
Hiasl's story began in 1982 when, as a baby, he was taken from Sierra Leone and smuggled into Austria in a crate with seven other chimps destined for a vivisection laboratory east of Vienna.
But customs officers seized the crate and Hiasl was sent to an animal sanctuary. Now the sanctuary faces bankruptcy, and Hiasl could be sent to the Baxter vivisection laboratory after all.
Seeking to save Hiasl, who likes painting, kissing visitors and watching wildlife programmes, an Austrian businessman has donated €5000 ($9270) towards his upkeep.
But unless Hiasl has a legal guardian who can manage the money it will go to the receivers.
As only humans have a right to legal guardians, his campaigners say it is necessary for Hiasl's survival to prove that he is one of us.
Primatologists and experts - from the world-famous primate campaigner Jane Goodall to Professor Volker Sommer, a wild chimp expert at University College London - will give evidence in the case, which is due to come to court in Vienna within months.
One of their central arguments will be that a chimpanzee's DNA is 96 to 98.4 per cent similar to that of humans - closer than the relationship between donkeys and horses. They will cite recent findings that wild apes hunt with home-made spears and can fight battles and make peace.
In New Zealand, apes - including gorillas, orangutans and chimpanzees - were granted rights as "non-human hominids" in 1999 to give them protection from maltreatment, slavery, torture, death and extinction.
Paula Stibbe, from Britain, has applied to be named Hiasl's legal guardian.
She said: "He is a colourful character with lots of energy. The least we can do for him is give him ... a future in society."
Barbara Bartl, the judge and an animal rights campaigner, has stalled proceedings until documents are provided proving Hiasl has, as his friends say, the status of an asylum-seeker, having been abducted from Sierra Leone.
If Hiasl is granted human status, Martin Balluch, of the Association against Animal Factories, who has worked to bring the court case, wants him to sue the vivisection laboratory.
He said: "This should, at the very least, mean his old age pension is secure."