The Putnams are eager to believe in the witchcraft accusations because of two separate reasons. They have suffered the loss of seven infants, they only have one child left, Ruth, who is now "sick."
Mr. Putnam declares that he comes from a large family and it can't possibly be his genes that produced weak babies. He is one of 11 sons and seems convinced that there is some other force at work that has caused the death of his seven infants.
Mrs. Putnam is eager to find someone to blame for her heartache at losing seven babies. She is particularly jealous of Rebecca Nurse who has many children and grandchildren.
"Goody Putnam is "a twisted soul . . . a death-ridden woman haunted by bad dreams." The death of all of her children has affected her deeply. Her pain has been turned into a vindictiveness which is directed at Rebecca Nurse."
In addition to the loss of their babies, the Putnams also have vendettas with several neighbors. Mr. Putnam has designs on his neighbors land, particularly poor George Jacobs, an elderly man who has 600 acres next to the Putnam land. He puts his daughter Ruth up to the task of accusing Jacobs of sending his spirit out to harm her. Putnam, the wealthiest man in town, is eager to buy Jacobs land to enlarge his property.
"Putnam is "a well-to-do hard-handed landowner" who attempts to benefit from the accusations made against other members of the community. Knowing that the convicted will be forced to sell their land for much less than it is worth, Putnam is all too eager to attain these properties at cut-rate prices"
Historically, not only did the Putnams eagerly accept the witchcraft accusations on the Nurses, there's some evidence they actively promoted the accusations! These two families had been at odds over land boundaries for years, among other issues. Accusing the Nurses of witchcraft would discredit them in the community; additionally, if declared a witch, one's land was forfeit; the Putnams would stand to gain if Nurse land became available. In terms of conflicts as presented in the Crucible, see the link: