Dr Harlow

https://www.youtube.com/watch?v=OrNBEhzjg8I

Doctor Harlow performed experiments on infant monkeys to answer the question does love exist?
He gave the monkeys makeshift surrogate mothers. One mother was made of soft woollen material while the other was wire. The soft one provided comfort but the wire one was the 'mother' installed with a feeding bottle. The monkeys would use the bottle on the wire mother but then instantly return to the soft mother. And when startled with loud machinery the monkeys instantly ran to the soft mother for protection. Once at the mother the monkey gained confidence and started screeching back in defence.
A second experiment he did was the pit of despair. Again infant monkeys were the test subjects as they are taken from their mothers at an early age and therefore you can see if its instincts will come through naturally. The pit was a upside down trapezium shape, the sloping sides made it impossible for the monkeys to climb their way out. Most monkeys stopped attempting to after the first two days. The monkeys were confined to the pit for the first year of their life. When they were released from the pit they were psychotic, depressed and uninterested in the opposite gender. But Harlow had wanted to see if they could be parents themselves. So he invented the 'Rape Rack' so that they could still be inseminated. But the monkeys who did conceive were too traumatised to care for their child at all.
Harlow's experiments have since been identified as cruel and are still up for much debate between animal rights activists and the science community.

Animal rights are a much more widely recognised thing nowadays and many products have 'no animal testing' printed on the fronts of packaging almost as a selling point rather than a disclaimer.