Seemingly insignificant daily practices, such as sugar usage in tea, can have a great accumulated impact on societal issues, such as obesity. That is why these behaviours are often the target of nudge interventions. However, when these behaviours are performed frequently they may turn into habits that are difficult to change. The aim of the current study was to investigate whether a portion size nudge has the potential to work in accordance with (instead of against) existing habits. Specifically, it was tested whether a portion size nudge would be more effective in reducing the amount of sugar added to tea, when people have a strong habit of adding a fixed amount of teaspoons of sugar to a cup of tea. The study (N = 123) had a mixed factorial design with teaspoon size (reduced size vs. control) as a within-subject factor, and habit disruption context condition (hot tea vs. cold tea) as a between-subjects factor. A paired t-test indicated that this nudge reduced sugar intake on average by 27% within subjects. When the context allowed for automatic enactment of the habit, the effectiveness of this nudge was moderated by habit strength. Surprisingly, the nudge effect was actually less pronounced when people had a strong habit. Implications for effective nudge interventions are discussed.

中文翻译：

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轻推效果的（苦）甜味：习惯在份量轻推中的作用，概念研究证明

看似微不足道的日常习惯，例如茶中糖的使用，却会对肥胖等社会问题产生巨大的累积影响。这就是为什么这些行为往往是轻推干预的目标。然而，当这些行为频繁发生时，它们可能会变成难以改变的习惯。当前研究的目的是调查份量轻推是否有可能符合（而不是反对）现有习惯。具体来说，当人们有在一杯茶中加入固定量的茶匙糖的强烈习惯时，测试了份量轻推是否会更有效地减少添加到茶中的糖量。该研究（N = 123）采用混合因子设计，将茶匙大小（减小的大小与对照）作为受试者内因素，和习惯破坏上下文条件（热茶与冷茶）作为受试者之间的因素。配对 t 检验表明，这种轻推使受试者的糖摄入量平均减少了 27%。当环境允许习惯自动形成时，这种推动的有效性会受到习惯强度的影响。令人惊讶的是，当人们养成强烈习惯时，轻推效应实际上不那么明显。讨论了对有效助推干预的影响。