Answer:
Environment
Explanation:
In a research study, internal validity refers to how well an experiment was carried out and to what extent the piece of evidence supports a claim.
The lesser the chance of confounding in a study the higher the internal validity.
Study of memory is possible through learning the electrical activity created by neurons.
Therefore, thunderstorm will affect the readings hence it is an Environmental threat to the internal validity.
Children who experience early puberty have higher rates of depression and anxiety compared to their peers. This effect is found consistently in girls, but findings involving boys are less clear.
Baby’s come from the sky and the bird brings them done to your doorstep
