Riley attempted to find whether rotation stress would affect the function of the immune system.
Riley measured the quantity of T cells in the rats' blood before and after rotating their cage for a duration of 3 hours. As there was an evident decrease in T-Cell quantity after the rotation, it was deemed an effective stressor.
He injected 2 groups of rats with cancerous cells.
Group 1: The rats were rotated for 10 mins every hours for 3 days (high stress condition)
Group 2: The rats were not rotated (low stress condition-control group)
Group 1 (High stress condition): The rats developed large tumours and some of them died as a result.
Group 2 (Low stress condition): Showed little to no signs of tumour growth or negative side effects.
Riley showed that the more stressed the rats became, the more likely they were to develop cancer.
However, it was in rats and so cannot be generalised to humans as we may work differently to rats.