What is meant by cruelty in a divorce action?

Cruelty, both mental and physical, is a traditional fault. Often the cruelty was mental, which is a catchall term that often meant that one spouse verbally and psychologically abused the other.

In some jurisdictions, cruelty is called extreme cruelty or cruel and inhuman treatment, which can be "as innocuous and benign as a pattern of conduct resulting in repeated annoyance or just about anything that makes it unreasonable or unhealthy for the parties to continue to cohabit as spouses." In many jurisdictions, court interpretations of the meaning of this legal phrase have been so diluted that it functions as "irreconcilable differences" in no-fault states.

In general, cruelty doesn’t mean just being mean, nasty or disagreeable to one another, but rather that unnecessary physical or emotional pain is being gratuitously inflicted by one spouse upon the other. Thus, Bessy Smith’s classic blues song "Mean to Me," a lamentation of the sorrows of a loving women trapped in a bad relationship with a nasty man, probably would not be grounds for divorce, then and now.

Cruel and inhuman treatment may mean either physical or mental cruelty to the degree "that makes it unsafe or improper for the parties to reside together as man and wife." Often there is a time limit for this conduct, often within five years before filing for divorce,

Cruel and human treatment means more than incompatibility. Incompatibility is not getting along and function as partners. Cruel and inhuman treatment involved "physical, emotional and financial abuse," including physical attacks, such as beatings; gambling away money; unexplained absences from the home; dating someone else and/or abusing the children.