While most consider it a fashion statement, it turns out that there's actually quite a bit of science behind facial hair. Different types go in and out of style, and men have many options. However, the way society perceives beards, mustaches, and stubble stays relatively consistent.
Obviously, it's impossible to say what type of facial hair is better. Some women find a full beard attractive, while others prefer men to be clean shaven. Gentleman also have their own preferences for their personal style. Some refrain from shaving because they like the look, while others find shaving to be a hassle or chore. Some groom in line with current trends, while others prefer more eccentric styles. A man can choose to follow the example of his father or listen to the preferences of his wife. There are even events like No Shave November, which partners with The American Cancer Society to raise money and awareness for charity. There's a lot that can be done with this distinctly masculine trait.
Whatever a man chooses to do, society will have opinions. A distinctive look achieved with this kind of grooming is associated with traits like aggression and dominance. Growth above the lip and along the jaw is caused by testosterone. Because of that, many people may get the impression of those with full growth to be angry, dominant, or aggressive. Clean shaven persons are regarded as social, healthy, and clean. One is not always more positively perceived than the other, however. A man who can grow a beard may also be thought of as more mature, masculine, and powerful than bare-faced counterparts. Those who shave completely appear more sociable and better able to integrate with others. Older males may find they look more youthful with a bare jawline. While more research is needed, it's interesting that society gathers such distinct impressions regardless of actual personality traits.
Of course, in the end, it all comes down to personal preference. There are no health or safety risks to shaving or not shaving. Trends change all the time, and it's a man's unique privilege to choose which to adopt and which to ignore. It's possible to be clean shaven during the week, taking advantage of the positive impression it gives. A man can then choose to let stubble come in over the weekend, sporting an entirely different look and the perceptions that come with it for a few days. Most are influenced by work dress codes, parents, spouses, and their own tastes rather than society's impression of their personal grooming.