Whole life dividends come from mutual companies, and that isn't a coincidence. It falls out of who owns the company.
A mutual insurer has no shareholders. The policyholders own it. When actual mortality, expenses, and investment returns beat the conservative assumptions baked into the premium, the surplus goes back to the owners, and the owners are the people holding participating policies. That return is the dividend.
A stock insurer is owned by shareholders who bought stock. Profit goes to them. A stock company can still sell whole life and can still pay something it calls a dividend, and the surplus has two claimants instead of one, with quarterly earnings expectations sitting on management in a way they don't at a mutual.
The practical difference shows up in time horizon. Mutual carriers make decisions on a fifty-year clock because their obligations run that long and nobody's asking about next quarter. Several of the large mutuals have paid a dividend every year for more than 150 years, through the Depression and two world wars. That record is the argument for the structure.
Demutualization is the thing to know about. A mutual can convert to stock ownership, and when it does, policyholders typically receive stock or cash in exchange for their ownership interest. Several large insurers did this in the late 1990s and early 2000s. If you're buying a participating policy for a fifty-year dividend, the structure you're buying into isn't permanent.
It doesn't make mutual automatically better. Stock companies dominate indexed universal life and term, they're often priced more competitively, and a well-run stock carrier with strong capital is a fine place for a death benefit. The structure tells you where the incentives point, not who wins.
Some companies sit in between. A mutual holding company owns a stock insurance subsidiary, which lets the group raise outside capital while keeping policyholder ownership at the top. If you're comparing carriers on structure, find out which of the three you're looking at before you weigh it.