Stand Growth

This is an explanation of an inconsistent phenomenon occurring in JoJo Bizarre Adventure's Stands and their Users. See the Stand Type page for Stand Evolution, a similar phenomenon.

Stand Aging
Many Stands, being physically and mentally tied to their users, have displayed change in abilities and appearance due to their user aging, be it natural or otherwise. Different methods carry different effects. This has never been addressed by Araki, but has been inconsistently implied.

Sethan
Alessi's Stand, Sethan, has the ability to turn anyone who touches its shadow younger.

Silver Chariot
During its first demonstration of abilities it turned Jean Pierre Polnareff into a 7-8 year old, de-aging his Stand with him, making it weaker, smaller, and slower. Upon the second use on Polnareff he was turned 4, and Silver Chariot was changed accordingly. Despite being weaker, the Stand still existed, as Polnareff was born with his Stand. Due to this it is likely that other born Stand Users like Avdol and Kakyoin would retain their Stand regardless of age.

Star Platinum
Upon encountering Jotaro Kujo and using Sethan on him, Alessi turned Jotaro into a 7-year-old, causing him to temporarily lose his Stand ability due to him not having it until the age of 17. It can be interpreted, however, that Jotaro retained his Stand, but due to Sethan's power also reverting the target's mind he forgot how to manifest it.

Sex Pistols
Despite Guido Mista being under the influence of The Grateful Dead's ability, his Stand, Sex Pistols didn't show any signs of aging before direct contact with Prosciutto, The Grateful Dead's user. This could be attributed to the fact that Sex Pistols is a colony Stand, and damage and effects are distributed differently than single humanoid Stands. After the contact induced aging, Sex Pistols shrank and became paralyzed.

Sticky Fingers
After warming up in the train's cabin, Bruno Bucciarati started rapidly aging. This did not affect his Stand, Sticky Fingers, visually, but it did slow it down to the point where Grateful Dead could out-maneuver it.

Dirty Deeds Done Dirt Cheap
Upon interaction with Ball Breaker, Dirty Deeds Done Dirt Cheap is rapidly aged due to Funny Valentine's own rapid aging. This causes the Stand to shed an outer layer of armor and lose its signature bunny ears. After Funny Valentine regains his youth the Stand is not reverted and stays in this shape for the rest of the part. Its powers are not affected.

The difference of permanent Stand appearance alteration could be due to this interaction happening in the Steel Ball Run and JoJolion universe, separate from the original Parts 1-6 universe, in which there are minor Stands logic differences.

Standard Aging
Standard aging seems to be the least effective on the Stands, only partially altering the Stand stats and creating minor visual differences.

Star Platinum
Star Platinum's appearance changes between Stardust Crusaders and Diamond is Unbreakable. In the anime the ankle high boots now go up to the knee, and its belt loses the two ellipses on the sides of its waist. In the manga the gloves now have holes on the inner side of the arm, akin to those The World wears. In Stone Ocean Star Platinum loses the elbow guards. All of these changes can be attributed to the change in art style, as Star Platinum's original manga appearance is vastly different from its appearance in the later chapters of Part 3 which only takes less than 3 months, making it unlikely to have changed due to age.

Its abilities are affected by Jotaro's Time Stop decreasing to 2 seconds in Part 4, which could be amounted to lack of usage which was likely the case as the Stand regained the 3 seconds of Time Stop after Jotaro regained its disc in the later chapters of Stone Ocean. With this change Star Platinums' persistence dropped to E, which is unlikely to have happened due to the Stand becoming a disc, as other Stand transfers did not affect the Stand itself.

Hierophant Green
Hierophant Green's only age related change is the change in size, as it has grown along with Noriaki Kakyoin.

Echoes Act 3
Echoes Act 3 did not change appearance within the 3 years between Diamond is Unbreakable and Golden Wind. Its Stand stats did change, however. All of the stats decreased one tier except for destructive power which went from B to A, and its Precision which remained at C.