In the 150 years since British scientist William Farr's research, scientists still find that marriage correlates with better health: "Contemporary studies, for instance, have shown that married people are less likely to get pneumonia, have surgery, develop cancer or have heart attacks. A group of Swedish researchers has found that being married or cohabiting at midlife is associated with a lower risk for dementia. A study of two dozen causes of death in the Netherlands found that in virtually every category, ranging from violent deaths like homicide and car accidents to certain forms of cancer, the unmarried were at far higher risk than the married."