A study published in “Social Psychological and Personality Science” claims that the inclusion of smiley emojis in work emails doesn't increase perceptions of warmth and actually decreases perceptions of competence. The study also shows that there's a glimmer of sexism in emoji usage. It revealed that when the gender of the email sender was unknown, recipients were more likely to presume that an email which included a smiley icon was sent by a woman.