How has our society been developing

Our society has been devel by creating new things

Explanation:

Modern humans evolved roughly 200,000 years ago and began spreading across the world. Across time, various groups developed their own ways of doing things, like creating their own cultures, or sets of productions, beliefs, and behaviors.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

world bank is the correct answer.