What 945 narrative bridges
reveal about oil-control shampoo.

One in three narrative bridges (32.8%) is a negation. Bloggers spend more rhetorical energy explaining what a good product is not — not fake-slippery, not scalp-stripping, not oil-control that dries you out — than what it is. This is the single most frequent bridge type, far exceeding direct sensory description.

Of the 310 negation bridges, 60.3% are core thesis statements (not noise), directly addressing efficacy, sensory mismatch, or safety. Only 6.5% are genuinely irrelevant context. Negation is the category's primary language of trust.

Both audited brand PDPs use zero negation definitions. They speak only in affirmation. The result: brands forfeit the right to draw boundaries around what their product does and does not do — bloggers draw those boundaries instead.

Of 229 time-stamped B-layer entries, next-day (27.9%) and extended/2 days+ (24.9%) together account for 52.8% of all sensory narrative. This is where consumers run their real efficacy test: the next-morning scalp check, the second-day volume decay, the third-day oil return.

Both Kérastase and Spes PDPs cover zero of these post-wash stages. Kérastase covers 4 of 7 timeline stages; Spes covers only 2 of 7. The moment consumers care about most is the moment brands say nothing about.

We call this the Somatic Black Box: the post-wash timeline where consumer trust is built or destroyed, but brand communication is entirely absent.

The Spearman correlation between A-layer (formulation) density and B-layer (sensory) density is ρ = 0.09, statistically not significant. This means: products with rich ingredient narratives do not systematically produce rich body-feel narratives. The two layers are independent systems.

Meanwhile, B↔E↔F form a tight triangle (all ρ > 0.69): body-feel, emotion, and bridge logic move together as a unified narrative unit. When bloggers describe body-feel richly, emotional and rhetorical richness follows. When they don't, no amount of ingredient data compensates.

A-layer is absent in 42.5% of products. Most bloggers lack ingredient literacy. But the structural message is deeper: even when A is present, it doesn't feed B. A separate translation layer — "what this ingredient should feel like" — is required.

Within the Somatic Black Box, 121 entries reveal the body-feel proxies consumers use to judge efficacy. Oil return speed dominates at 53.7% (65 entries), followed by scalp sensation (13.2%) and oil return volume (9.1%). This is the somatic-efficacy causal chain: consumers infer whether the product "worked" not from ingredient labels, but from how quickly oil comes back.

The next-morning scalp check is the single most important judgment moment. Next-day entries skew negative (48% vs 36% positive), while extended entries are more balanced — suggesting that the 24-hour mark is where trust most often breaks.

Among 310 negation bridges, the breakdown is stark: efficacy gap = 38.4% (119 entries), sensory mismatch = 19.0% (59), while trust/brand negation accounts for only 4.8% (15). The fix is adjusting how you promise, not who you are.

Within the efficacy cluster, three sub-themes dominate: oil-control efficacy verification (33), oil-control duration/decay curve (37), and the "oil control ≠ dryness" reframe (34). The third is particularly significant — bloggers are actively redefining what "good oil control" means, moving from "how long until oil returns" to "clean without damage."

138 category assumptions were extracted from 67 narrative terrains. When mapped against two brand PDPs: Kérastase responds to 35.5% (Y+P), Spes responds to 40.6%. 46.4% of assumptions are unanswered by both brands. This is not an individual oversight — it is a systematic blind spot.

The pattern by L1 category reveals strategic choices: Spes scores 78% on trust/brand assumptions (clinical data works), but 0% on care/gentleness — it trades one dimension for another. Kérastase's weakest area is price/value at 14%. Both are weakest on the largest block: efficacy (73 assumptions, ~36% response).

Kérastase: over-promise → anger. The "3-day challenge" claim sets a precise expectation. When bloggers test it at hour 24 and it fails, the A-layer edifice collapses. Emotion profile: 64% negative, led by disappointment and contempt. The brand narrative promised too much in a dimension consumers can directly verify.

Spes: under-describe → ambivalence. Clinical data and national certifications build A-layer authority, but the PDP covers only 2 of 7 sensory timeline stages. Without body-feel anchors, bloggers land 38% ambivalent — "fine but not exciting." The brand provides evidence but not experience.

Both end in the same place: bloggers constructing their own narrative that diverges from PDP intent.

63.4% of products have zero life-context. Bloggers describe what shampoo does but almost never where, when, or in what life situation. Among the 49 products with any scene data, daily routine dominates (34.7%), while the two moments consumers arguably care most about their hair — commute (3 mentions) and social occasions (1 mention) — are nearly absent.

Critically, 34 products have next-day body-feel data but zero life context. Consumers report how their scalp felt the next morning, but never say what they did that day. This is a natural pairing that neither bloggers nor PDPs make.

Scene richness is blogger-dependent, not product-dependent: some bloggers embed scenes in 100% of reviews; others in 0%. PDP cannot rely on bloggers to provide scene context — it must build its own.

Of 402 sensory entries, tactile dominates at 51.5% and visual follows at 26.9%. Olfactory accounts for only 13.2% (53 entries), despite scent being a primary personal-care differentiator. Most scent mentions are binary — "smells good" or "smells bad" — rather than descriptive.

Olfactory entries cluster in the scent-retention stage. During application and immediate post-wash — the two stages bloggers discuss most — scent is virtually absent. Bloggers lack scent vocabulary for shampoo (unlike fragrance categories where scent language is rich and layered).

This is an ownership opportunity: PDP that provides scent anchors ("a clean herbal note that fades by hour 6") fills a vocabulary gap bloggers cannot fill on their own.

243 emotion entries split almost perfectly: 45% positive, 45% negative, 10% ambivalent. The category is evaluated in binary terms. Top negative emotions are high-arousal: contempt (31), anger (19), disgust (9). Top positive: trust (23), satisfaction (21), surprise (19). The emotional middle ground is nearly empty.

But the most revealing data point is the contradiction rate: 42% (102 entries). Bloggers frequently hold two emotions simultaneously — "effective but too harsh," "nice scent but terrible wash-feel," "works but not worth the price." These contradictions are the most honest emotional data in the corpus.

PDP emotion is universally promotional (positive only). Neither brand inhabits the ambivalent middle where purchase decisions actually live. A PDP that acknowledges trade-offs — "effective and gentle" — mirrors how consumers actually feel.