In work specific knowledge leads to a higher salary. Peoples wants and needs are focused on one thing at a time. When they make a purchase they need experts to direct them to the best service or product suited to them. This will depend on the price the relevance and the quality of the product concerned.
It is also true in the field of hobbies and interests The more passionate the individual is in their interest the more they want to surround themselves with others who know a great deal about their shared passion.
When we need something essential for life specific knowledge comes out on top. If someone needs heart surgery they require a heart surgeon not a general practitioner. Expertise grew from a time when division of labour became the pattern of society. Primitive mankind would need to do everything to survive but when we stopped hunter gathering and started to settle into farming society became stable enough to divide our labour to focus on specific skills
General knowledge also has its advantages. Socially general knowledge hoovers up many more friends and acquaintances. The more general knowledge people have the more they can find in common with those they meet. When searching for a life partner, general knowledge will help us connect on those precious early dates. It is folly to assume those with general knowledge are of less value in society than those with specific knowledge. Some of course have a degree of both. Many careers need general knowledge as well as specific knowledge especially in the field of sales where general knowledge can create rapport before the sales process begins.
I think of general knowledge as a vacuum cleaner in terms of human conversation and interaction. Specific knowledge is the sifting through the cleaners bag looking for those bits that are of greatest benefit to all concerned .
Peter Bull ( Author of Get In Touch With Your Inner Quizmaster )