It is a perusal act to know about the instinctive activity of a human brain that is an unconscious, involuntary, or physiological activity, in that, an action or reaction is involved. On the contrary, the distinctive activity of a human brain is superconscious, voluntary, or psychological activity, in which, distinction is clearly marked. Besides, the subconscious and conscious activities are also relatively the parts of former and later. Previously, instinct was considered the motive power behind all thought and action. It is not the case as reflective activity of a human brain is based on distinction, the point of difference that which makes one thing different from another. It is the quality of being superior, excellent, or distinguished that make it distinctive activity. Distinction means serving to mark a difference or make distinct. Distinct, meaning thereby, easily heard, seen, understood, plain or clearly marked is different in kind or separate from instinct. Instinct is a natural tendency to behave in a certain way without reasoning or training. It is an innate impulse or a propensity toward a certain type of behaviour. Instinct is innate or inherited tendencies that are the motive power behind all thought and action. Instinctive activity, characterizing a behaviour pattern that is not learned. It is based on reflex. Reflex is a simple stimulus response sequence that is unlearned, common to all members of a species, and relatively unmodifiable by motivational factors. It is a mechanical act that appears not to involve volition or choice. In other words, it is a thoughtless, impulsive act. Moreover, reflex-action is an action that is independent of the will, being an involuntary response to a stimulation of the nerves. It is pertinent to mention here that the most important things follow. Nerve is a fibre or bundle of fibres carrying feelings and impulses between the brain and all parts of body. It is a condition of being easily excited, worried, irritated, or frightened. On the other hand, It is a quality of being bold, courageous, self-reliant, or audacious. Make great efforts if needed the later from former. In addition, the craniosacral division of the autonomic nervous system that arises out of the medulla and lower spinal cord consists the cranial nerves of the roof brain. In addition, impulse is an impetus, that is, force with which a body or mind moves or driving force. It is a sudden inclination to act without thought about the consequences. Impulse is the outcome of stimulation that is thrust upon an individual or that pushes toward action. It is a state of mind, in which, such inclinations occur or a tendency to act without reflection. Distinctive activity of a human brain if one is free from stereotypes or is not prejudiced, is dependent upon the contents of reflective activity that takes into acccount the thorough knowledge of the subject. It is also a state of mind, entirely different from instinctive activity, in that, strong inclination occurs to reflect. Reflect that means throw back (light, heat or sound; or the elements of consciousness-image, sensation or affective state in a fraction of a moment), express, show the nature of, bring something upon somebody (credit or discredit for good or bad), consider, or think on, at present, what ? It is an exploration devoid of selfish ends or an exploitation toward selfish ends.Sensory-motor activity of a human brain (the outcome of reflex arc) is also a mechanical act for volition or choice due in course to the reflective activity(plus/minus/conflict) in an autonomous way. It is a thoughtful and not impulsive act.