(dissenting, with whom Liacos, J., joins). The court today departs from its test “whether ‘anywhere in the evidence, from whatever source derived, any combination of circumstances could be found from which a reasonable inference could be drawn in favor of the plaintiff. ’ ” Poirier v. Plymouth, 374 Mass. 206, 212 (1978), quoting Raunela v. Hertz Corp., 361 Mass. 341, 343 (1972). Because the court departs from its test, I dissent.
I agree with the court that the clerk’s1 comparison of signatures is some evidence that Kemper was not negligent in processing the change of beneficiary form. There was, however, other evidence which indicates negligence on the part of the company. William Jones, the former head of the policyholder service department, said that Kemper required a disinterested third party to witness the signature of the insured. Jones also stated that the beneficiary of a policy would not qualify as a disinterested witness.2 Jones’s successor said that she eliminated Kemper’s requirement of a disinterested witness, although there was no evidence she had authority to do so.
The jury could have believed the testimony of Jones that a signature of a disinterested witness was required on a change of beneficiary application and that, because there was no sig*861nature of a disinterested witness on the forged application, Kemper had failed to follow its own internal procedures developed to protect against fraud and foul play. The failure of Kemper to follow its company procedures is some evidence of negligence. See Kushner v. Dravo Corp., 339 Mass. 273, 277 (1959); Kelly v. Boston & Me. R.R., 319 Mass. 603, 613 (1946); Stevens v. Boston Elevated Ry., 184 Mass. 476, 478-479 (1904).
Moreover, the evidence indicates that Bacon had submitted an application to change the beneficiary of his life insurance policy in September, 1973. After this change was processed, Bacon wrote a letter expressing concern to the company regarding the change of beneficiary procedure because the amount of the policy was a significant amount of money to his family.3 Nine months later, Kemper received a second change of beneficiary application bearing the forged signature of Bacon shifting the proceeds of the policy away from his family. Jones stated that, on the basis of this information alone, he might have been suspicious of the requested change of beneficiary and would have inquired further into the matter before processing the request for a change. • Although the Kemper clerk had Bacon’s entire file before her in processing the change of beneficiary and could see the prior correspondence regarding the change of beneficiary procedures, she did not investigate this change of beneficiary request. If the jury credited Jones’s testimony and rejected the clerk’s actions in only comparing the signatures, that was evidence that Kemper violated its duty to act with reasonable care with respect to Bacon. The credibility of the witnesses is for the jury and it is inappropriate for this court to substitute its judgment on questions of fact. See Cullen Enterprises, Inc. v. Massachusetts Property Ins. Underwriting Ass’n, 399 Mass. 886, 897 (1987); Lupia v. Marino, *862353 Mass. 749 (1967). See also Foley v. Polaroid Corp., ante 82, 104 (1987) (Liacos, J., concurring).
Although I believe a per se rule which imposes a duty on insurance companies to verify all change of beneficiary applications is inappropriate, on the basis of the facts of this case, the jury could reasonably have inferred that Kemper had a duty to investigate more fully this change of beneficiary. The insured took extraordinary steps to inform Kemper of his concerns for his family and, only nine months later, the insured seemed to have had a dramatic change of heart, switching the beneficiary away from his family, and this change was witnessed by the new beneficiary. These facts support the jury’s determination that Kemper was negligent in handling this particular change of beneficiary application.
In addition, although not required by law, Kemper required a beneficiary to have an insurable interest in an insured’s life. While a partner has an insurable interest in the life of another partner, the evidence showed that Kemper made no attempt to ascertain whether Blaikie was, in fact, a partner of Bacon.4 The clerk simply accepted the application for change of beneficiary without any further investigation. The jury could have found that this failure of the clerk to verify that the company policy concerning insurable interest was adhered to in this application was evidence of negligence.
Finally, there was evidence that the Kemper’s clerks responsible for change of beneficiary applications handled ten to twelve requests a day. The jury could reasonably have inferred that the benefit from scrutinizing those few applications which were witnessed by the new beneficiary outweighed the cost of doing so. Kemper’s failure to scrutinize those few applications *863would permit a reasonable inference that Kemper failed to exercise due care in the circumstances.
There was evidence which, if believed, provided a factual basis for an inference that Kemper did not take reasonable steps to determine whether Bacon consented to the change of beneficiary. Instead of adhering to well-established principles of review, the court makes the factual determination that Kemper acted with reasonable care. On the evidence admitted, the jury could have found that Kemper acted reasonably or the jury could have found that Kemper failed to follow its own procedures and exercise a reasonable amount of care in processing the change of beneficiary form. The jury could properly have concluded that Kemper was negligent. “[W]e have no authority to take upon ourselves the duties of a tribunal of fact, and to determine what verdicts should have been rendered by the jury.” Electric Welding Co. v. Prince, 200 Mass. 386, 392 (1909).
The court’s decision today “trenches on our long-established, consistently applied, and zealously guarded line of demarcation between the respective roles, functions, and responsibilities of the judge and of the jury.” Commonwealth v. Dickerson, 372 Mass. 783, 802 (1977) (Quirico, J., concurring). “Jurors saw the witnesses, and their judgment of the credibility of the witnesses, of the comparable strength of the conflicting evidence, and of the factual validity of the contentions put forth by each side should be immune from attack. It is the jurors who decide questions of fact, and who apply the law to the facts, not judges. ” Bonin v. Chestnut Hill Towers Realty Corp., 392 Mass. 58, 77-78 (1984) (Abrams, J., dissenting). The court’s decision deprives the plaintiffs of the right to have the jury decide the facts and usurps the jury’s rightful role, thereby “diminishing the extent of citizen participation in the administration of justice and the many benefits which flow from such participation.” Commonwealth v. Canon, 373 Mass. 494, 516 (1977) (Abrams, J., dissenting), cert. denied, 435 U.S. 933 (1978).
The facts support a conclusion that “[m]ore than one decision was possible to honest and reasonable [persons], and, therefore, *864the jury was the tribunal to determine which one.” Hicks v. H.B. Church Truck Serv. Co., 259 Mass. 272, 277 (1927). In sum, the judge correctly denied the motion for directed verdict and the motion for judgment notwithstanding the verdict. I respectfully dissent.
I note that there was no evidence that the clerk was trained in handwriting analysis.
The court states that Jones did not explain how the requirement of a disinterested witness could protect against fraud or foul play. Ante at 855. This observation misses the mark. The jury could use this evidence that Kemper was not following its own internal policies and procedures in determining the issue of negligence. The jury was not asked to assess the appropriateness or effectiveness of Kemper’s internal procedures.
Bacon’s letter to Kemper stated that he thought Massachusetts law required a change of beneficiary form to be accepted in writing by the company and signed by an officer of the company. Bacon stated that this acknowledgement requirement was the only way to assure that both the insured and the company are aware of the change. He stated that he was anxious about this matter because the amount of the policy was “a lot of money to my wife and kids.”
As the court states, ante at 854, “[I]t is immaterial who was listed as the beneficiary.” This statement is far too broad. Pursuant to Kemper’s own policies, the beneficiary must be one with an insurable interest in the life of the insured. If the beneficiary named on an application is not such a person, it would be further evidence that Kemper is not following its internal policies and procedures, and evidence which the jury could use to determine whether the defendant was negligent. Although this does not aid the plaintiff here, the court’s statement is too broad.