There could be many different reasons.
farming collectives
security needs
The answer to this question is Ernst Weber
This finding was correlated to how intense is a person' reaction when receiving a certain stimulus. According to his finding, when a person receive two fold stimulus from the previous one, that person will not necessarily display two fold intensity because of the thresold.
Technically they can, but the line is less sloped
Exponential growth refer to a condition when the number of population is rapidly increased in a higher rate. Organisms that take long time to reproduce can experience an exponential growth if a large number of organisms reproduce together within short period of time.
hope this helps
The shape of the contitintes*