likelihood of survival

What Demasio means by these characteristics increasing the likelihood of survival is that the self and sense of self allow humans to open up their options to which they survive. A starfish is sensitive to light and dark, so when in danger they have only the option of natural instinct, being to change their surrounding based on light or dark. A human being has prior experiences and can remember what has worked for them in the past to survive, they can create new options, and continuously find new ways to survive if what they are currently doing is not working. As the world around us changes, survival tactics must likewise change. This being said, animal natural instinct may not be sufficient for survival in the newest of surroundings- whereas a human who has a sense of self can naturally increase their awareness of what is happening around them and try to adapt since they are not constrained to simply one survival tactic.