Life insurance firms may have unexpectedly benefited from mortality and morbidity underwriting in 4Q13, though it’s still early and not all companies have reported their earnings. “It appears mortality and disability underwriting results have been pretty solid,” says Sterne Agee analyst John M. Nadel. Although this is based on just three companies reporting (StanCorp Financial Group, Inc. (NYSE:SFG), Symetra Financial Corporation (NYSE:SYA), and Reinsurance Group of America Inc (NYSE:RGA)), the same underlying trends should have a similar impact on these companies’ peers. Mortality providing modest upside StanCorp Financial Group, Inc. (NYSE:SFG) beat expectations based largely on mortality underwriting for group…