Scent has been considered as an important factor to influence the appetite. It was discovered that there is a close relationship between sense of smell and diet(Dow, 2007). Different types of scents could cause different impressions between groups and similar impressions within groups. For example, scent of freshly baked cookies are one of the external hunger cues(Festjens, Bruyneel, & Dewitte, 2018). Therefore, the study tries to learn the effect of scents in these classifications, and choose a typical scent under different types is large in number.  From previous research, Shen and his group(2005) examined the effect of fruigraps oil scent, and found that the rats’ appetite and weight decreased. The experimental design was inspired by another experiment that learned the olfactory impression of lip balm(Kikuchi, F.2013).

Subjects evaluated their impression about the lip balm of citron and vanilla in scales. The citron lip brought strong feeling of “clear”, and the vanilla lip balm brought feeling of “soft”. The study by Reed(2008) shows that there are effects of peppermint scent on appetite control and caloric intake. It is thus believed that the different feelings may influence people’s appetite differently without neuro activities’ effect. The soft feeling scent, like vanilla and lavender,  may increase people’s appetite. Then, a hypothesis is proposed that people will show highest likeability to vanilla favored conditions; the second highest could be shown to lavender flavored condition; the lemon flavored should have the least likeability.

It is expected that people tend to desire food with savory and flowery scents more. The research result by Nikita et al also shows the cleaning scent would influence people’s judgement before creating a belief of certain feature. They asked the participants to rate the a new drug effect by reading the drug descriptive. The participants would rate the drug either in a room sprayed by cleaning scent or in a room with neutral scent. In the experiment result, it is found that participants in the room with cleaning scent significantly judge the drug more favorably than people in the neutral room. In generally, effect of cleaning scent would be a good  topic in various testing situation. Another former research by Hirsch et al also supports the result from Nilita et al, which placed two different odorants around two slot machines in a Las Vegas casino. As the control group, the third slot machine was isolated from the scent influence. The amount of money gambled in the three slot machine would be recorded. In the research result, it was found that people significantly increased their money one of the scented slot machines. This research showed clearer relationship about the scent effect on people judgement, even like relatively high risk activities. But this research didn’t showed strong relationship. Based on previous researches, a series of research questions can be posed: If interviewer would be affected by the cleaning scent from interviewee, then affect the interviewing fairness? Or should the scent using would be banned in stick recruiting interview ? Beside that,  cleaning scent also been used in many laboratory circustans. It is common for experimenter to use lemon scented wipe to clean experimental equipment. Will the cleaning scent of wipes influence participants’ judgement during experiment? Furthermore, if possible to use cleaning scent to help people improve their emotion in certain treatment?

Based on this, the research tries to have a direct look on the effect between different scents and human appetite based an empirical study. The research subjects are nine undergraduate students, who are collected through a convenience sample of PSY 3001 course. Given the limitation of experimental condition, the neuro activity wil not be involved but objects are required to evaluate their impression on questionnaire after randomly assigning one hundred objects in the experiment. The subjects will enter a room full of a specific scent(lemon, lavender, vanilla or no flavored). A questionnaire is using Qualtrics to collect participants’ attitude and ratings of quality of the chocolate. Subjects would be ask to eat a chocolate bar in 3 minutes. Then, they will leave the room and evaluate their likeability to the chocolate bar on a scale, which may reflect people’s’ appetite. Other food is added in later group discussion. ANOVA is also conducted to find the potential relationship between the scent effect and appetite. This research makes an attempt to figure out how scent influences the appetite by manipulating the smelling of room and see how subjects’ ratings of to same food (chocolate bar) under different conditions.