Overstimulation is the second characteristic of highly sensitive people in Elaine Aron’s DOES model.
Dr. Aron describes it as follows:
“If you are going to notice every little thing in a situation, and if the situation is complicated (many things to remember), intense (noisy, cluttered, etc.), or goes on too long (a two-hour commute), it seems obvious that you will also have to wear out sooner from having to process so much. Others, not noticing much or any of what you have, will not tire as quickly. They may even think it quite strange that you find it too much to sightsee all day and go to a nightclub in the evening. They might talk blithely on when you need them to be quiet a moment so that you can have some time just to think, or they might enjoy an “energetic” restaurant or a party when you can hardly bear the noise. Indeed this is often the behavior we and others have noticed most—that HSPs are easily stressed by overstimulation (including social stimulation), or having learned their lesson, that they avoid intense situations more than others do.”
Overstimulation is the characteristic that causes many highly sensitive people to feel that there is something wrong with them and to seek help. To non-HSPs it may seem like anxiety or a panic attack and from their frame of reference, HSPs seem to be making much ado about nothing. That is not the case, however. Sensitive people because of their energy sensitivity take in information that non-HSPs do not see, and so their overstimulation is as much a problem of the volume of information as anything else. The non-HSP’s nervous system does not absorb all the sensory information around them.
The Gift Of Overstimulation For Sensitive People
Overstimulation leads to depth of processing because highly sensitive people want to understand before they act. It is a little like being in a grocery story of sensory information. Just as you want to make informed decisions about what you buy, so you also want to make constructive decisions about responding to all of the sensory information you take in.
Unfortunately, sensitive people can be regarded as slow or overcautious when they are being thorough and conscientious. Taking the time to sort through sensory and other information is the beginning of the path to perceptual strength, confident constructive choices, and wisdom. Inner strength begins here.
 Author’s Note, 2012 for The Highly Sensitive Person, 9/6/2012, link.