This is probably wrong. It is too speculative to be true.
The atrophy of the thymus with age following the growth of the gland during puberty has been called the cause of aging by some.
In all likelihood, there is no single cause of aging.
Could these gerontologists actually have it backwards? Could a shrinking thymus provide a survival advantage?
If autoimmunity is real, could thymus shrinkage actually be a mechanism of delaying death from earlier onset autoimmunity due to continued over-activity of the immune system?
1. Growth of thymus during puberty protects against major infections in the critical early reproductive years.
2. But could atrophy of the thymus after puberty protect against earlier onset of autoimmunity?