Guinea Pigs Need Friends Too
Guinea pigs are herd animals therefore they do better in groups or in pairs it is acutely quite cruel to house one guinea pig by its self it is much nicer for the guinea pig to have a pair rather than just having one.
What if I spend lots of time with my guinea pig?
Guinea pigs need a companion of their own kind as well as their humane companion keeping just the one guinea pig is thinking more of what is easier for you and not what is best for the guinea pig some people believe that if they just have the one guinea pig they will bond with their humane owner more this is not true guinea pigs personalities very some are more people friendly then others. Guinea pigs personalities will not change weather they are on their own or not.
Guinea pigs living by themselves can develop many healthy, behavioural and psychological problems.
Behavioural and psychological
Loneliness, if you had to leave your guinea pig for the day he/she may get lonely and or depressed.
Boredom, Guinea pigs living by themselves can get quite board developing things like cage wire and or wood chewing, barbering of their own fur, stereotypic behaviour like walking back and forth over and over
Health
Weight gain, Guinea pigs living on their own tend to have compulsive weight gain always eating and wanting more food.
The boy myth
There is a very common myth about male guinea pigs this myth is that two males cannot live together happily this is infect just a myth males can quite happily live together as good friends all you need to do is take the proper steps to interdicting a new male.
It is a good idea to get a baby male to pair up with your adult this is much easier for you and your guinea pig. Guinea pigs can be quite dominant and territorial it is much easier to pair a baby with an adult as the baby will let the adult be the alpha male.
Recommended reading before trying to pair your guinea pigs up.
http://www.cavyspirit.com/sociallife.htm