Deep Breathing

If we try to simplify the developmental and evolutional perspective of ourselves and our society, it seems that we encounter the so-called three or four levels of categorization. I am not sure if such categorization is derived from the limitation of our perception or else might be related to some kind of archetypical commonalities. In my understanding so far, it may be more related to the biological limitation of our perception. One of the similar cases is that maximum sequence of number we can memorize at glance is at most 7 or 8 digits. As well-known, this is because of the biological capacity of short term memory of our brain. Although it may be possible to expand the number of digits by our intentional training, it seems that 7 or 8 digits are a default set up of our short term memory and its variance to be expanded can not be beyond additional 20% of such default setting. We can never memorize 20 digits of number unless we use a memory technique such as visual association or u