I'm looking for a word to describe a person or persons who are comfortable in their state of being or their position in life, who are unwilling or afraid to change for the better or even take a chance. I once read a book with the word in it, but I can't remember what it is.
A "slacker" is a person who avoids work or effort. Synonyms can include goldbrick, shirker, slouch, deadbeat, etc. These are all negative terms. Also, apathetic, blase, indifferent. "Content" or "satisfied" are more positive terms to describe someone happy with what he/or she has--also "fulfilled." A person who is afraid of change is a metathesiophobe. Many people who are not actually phobic about change but still resist it are described as "risk-averse," apprehensive, timid, etc.