The Confirmation Bias Effect in Sustainability Perception

There is a well-documented effect in consumer research: people who have recently purchased a brand rate that brand more favourably than those who have not. In sustainability perception, this effect is measurable and consistent enough to be called a structural feature of the data rather than statistical noise.

In the Australian F&G benchmark, recent purchasers of a given brand rate its social and environmental responsibility materially higher than non-purchasers of the same brand. The effect is present across all brands in the dataset. It reflects a combination of post-purchase rationalisation, greater information access through product use, and the general tendency to justify choices already made.

The practical consequence for measurement is significant. A raw comparison of brand SRS scores that does not account for purchase recency will consistently overstate the perception of brands with high purchase frequency and understate the perception of brands with lower penetration but strong ESG credentials.

The SRS methodology cancels this effect in benchmark data. When comparing the relative performance of brands, scores are adjusted so that the confirmation bias contribution is neutralised. What remains is the consumer perception signal that exists independent of purchasing relationship.

This matters particularly when assessing whether ESG perception is functioning as an acquisition driver rather than purely a retention driver. The leading brands in the Australian benchmark, brands like Who Gives A Crap and Earth Choice, show relatively small SRS differentials between purchasers and non-purchasers. That compression is the signal: these brands have communicated their sustainability credentials to the broader market, not just to customers.

Brands with large purchaser/non-purchaser differentials are still converting their ESG investments into perception, but that perception is contained within the existing customer base. It is not yet functioning as a switching catalyst for new consumers.

The SRS data can identify which situation a brand is in. That distinction is the starting point for any communication strategy decision.