Competing explanations for the Patterson–Gimlin film
A structured comparison of the biological, costume-hoax and image/measurement interpretation hypotheses.
H1 — Unknown biological animal
Status: unresolved
The footage depicts a real, unclassified large bipedal primate or hominoid.
- Surviving film is a physical/media artifact rather than testimony alone.
- Some analysts argue visible surface anatomy, limb proportions and motion are difficult to reconcile with a period costume.
- Film-image integrity work argues examined copies preserve analyzable information and do not show deceptive editing.
- No specimen, DNA, body or independently verified biological sample is tied to the event.
- Technical interpretation of proportions and gait depends on disputed scale/frame-rate assumptions.
- The subject's identity cannot be established from image integrity alone.
H2 — Human performer in fabricated suit
Status: unresolved
The event was staged using a human performer and a costume.
- Patterson had strong prior Bigfoot interest and was seeking film evidence.
- John Napier and later skeptics judged parts of the gait/form humanlike.
- Bob Heironimus later claimed to be the performer; Philip Morris later claimed to have sold Patterson a gorilla suit.
- No alleged original suit has been produced.
- Heironimus/Morris claims are decades-late and are disputed; descriptions reported in the literature are not fully consistent.
- No contemporaneous document in the present dossier proves a staged shoot.
H3 — Film artifact / scale / playback misinterpretation
Status: partial explanatory hypothesis
Some extraordinary-seeming features arise from camera motion, unknown frame rate, lens perspective, copy generation or later stabilization/enhancement.
- Frame rate at the moment of filming is not documented with certainty.
- Measurements of stature, speed and limb proportions depend on scale and camera assumptions.
- Later reproductions and stabilized versions can create or suppress apparent detail.
- Does not alone explain what physical subject was filmed.
- Image-integrity analyses argue useful original image data survives despite later copy artifacts.
Key methodological lesson
A good case dossier must allow both sides to fail. If future evidence makes a suit scenario untenable, that should become visible. If future evidence makes biological interpretation untenable, that should become visible too. The database should not need structural changes to accommodate either result.