[1][2] Jenny arrived at London Zoo from Borneo in November 1837, after being sold by a returning sailor called Mr Moss for £150.

[6] He wrote to his sister about Jenny in 1838: the keeper showed her an apple, but would not give it her, whereupon she threw herself on her back, kicked & cried, precisely like a naughty child.— She then looked very sulky & after two or three fits of pashion, the keeper said, "Jenny if you will stop bawling & be a good girl, I will give you the apple.

"— She certainly understood every word of this, &, though like a child, she had great work to stop whining, she at last succeeded, & then got the apple, with which she jumped into an arm chair & began eating it, with the most contented countenance imaginable.

[7]Jenny's reaction reminded Darwin of the behaviour of children, and he noted that she showed facial expressions of "rage, sulkiness and despair".

His notes also reveal that Jenny could obey instructions such as being asked to open a door, position herself ready for grooming and giving some things up.

He wrote in his notebook C:[10] Let man visit Ouranoutang in domestication, hear expressive whine, see its intelligence when spoken [to]; as if it understands every word said – see its affection.