Hereditary Hairstyle

For the record, the third generation male had the same hairstyle as well.

Seen that ridiculous hairstyle? Turns out it's hereditary. Most of the time, it's an Improbable Hairstyle and often a subtrope of Anime Hair. It is also a type of Strong Family Resemblance.

Can be seen as a Sub-Trope of both Generation Xerox and Identical Grandson.

Examples of Hereditary Hairstyle include:

Anime and Manga

Usagi and her Kid From the Future Chibi-Usa both wear their hair in exaggerated odangos in Sailor Moon. So does Queen Serenity, Usagi's mother... in a past incarnation.
- The parody manga Parallel Sailor Moon introduces daughters of the four Guardian Senshi, who look exactly like their mothers (hairstyles included) and have the same names.
Goku's younger son Goten from Dragon Ball has the same exact hair as his father, who has the same as his father Bardock.
- Likewise, Vegeta and his father, King Vegeta, have identically ridiculous hairstyles. It also has a rare cross-gender example in Dr.Briefs --> Bulma (when not permed) --> Trunks.
- The Non-Serial Movie explains Goku and company's hairstyle as belonging to a particular genetic type common to Saiyans in Bardock's (original) power level, as unrelated character Turles is shown to have the exact same look as well.
Yu-Gi-Oh!: Yugi's hair spikes are inherited from his grandfather, though this is less obvious until the chapter where we see Sugoroku as a young man.
Mahou Sensei Negima: Negi Springfield inherited his father's spiky red hair.
In Metal Fight Beyblade, Gingka and his father have the exactly same hairstyle, even with matching headbands. However, his father's hair is a darker red.
The Armstrongs in Fullmetal Alchemist all have blond hair with a distinctive curl in the front.
The eponymous Yaiba seems to have inherited his hair from his father.
In Nichijou, Nakanojou and The Daifuku Guy have mohawks.
Shobu's Disappeared Dad in Duel Masters shares his absurdly big Anime Hair.
Asem, the second-generation protagonist of Gundam AGE, has a more masculine version of his mother's short haircut + ponytail.
In Marginal Prince, Joshua's hairstyle is exactly the same like that of his father, with the color of his mother's hair. At the same time, it looks identical to that of his ancestor, King Alphonso. And then there is Henri, whose hair has the exact same color and style (including length) as his dead mother's.
Komachi from Yes! Pretty Cure 5 sports an identical hairstyle to that of her older sister Madoka (no, not that Madoka).
- Also, to a certain extent, all members of the Kurumi family sport wavy hair.
The Lyrical Nanoha franchise has an adopted child version with Vivio, whose Older Alter Ego shares the same side-ponytail hairstyle as her Nanoha-mama. She'd wear it in child form too if she could, but the Nanoha Striker S manga showed that all that concentrated hair causes her to tip over to the side.

Comic Books

Infamously, the Osborn family of Spider-Man (seen above), who all have that same... "style". The one exception is Gabriel Stacey, son of Norman Osborn and Gwen Stacey, and even in that case, it is likely because his father was originally intended to be Spider-Man himself.
- Spider-Man has a mother-daughter example in Gabriel's sister Sarah; apparently black hairbands are genetic. Apart from the arguable quality of the story that introduced them, this may be part of the reason fans are hoping for a Retcon.

Film

Meet the Robinsons: The Robinsons all have exactly the same flick in their hair, even most of the women.

Literature

Harry Potter got his jet black messy hair from his father, James.

Video Games

Emperor Uriel Septim VII and his illegitimate son (or should we say... heir?) in The Elder Scrolls IV: Oblivion bear some facial resemblance, but have the exact same hairstyle despite having never met (there are only a limited number of hairstyles available to begin with, but it does help you get the feeling they're related). But it gets better in light of one popular fan theory: it's possibly a hint that the Prophet in Knights of the Nine is Tiber Septim, a.k.a. Talos himself.

Webcomics

Homestuck: the kids have very similar hairstyles to their guardians, and, of course, each other.