“Based on exclusive ties of solidarity between ‘people like us’, exemplified by families, and is restricted to enabling people to ‘get by’.” (Edwards)
“Bonding social capital refers to the links between like-minded people, or the reinforcement of homogeneity. It builds strong ties, but can also result in higher walls excluding those who do not qualify, American college fraternities being a prominent example of such bonding.” (Schuller, Baron, & Field, 2000)

As defined by Edwards in the Social Capital encyclopedia entry. Schuller, T., Baron, S. & Field, J. (2000). Social capital: A review and critic. In S. Baron, J. Field, & T. Schuller (Eds.). Social Capital. Oxford: Oxford University Press.