An excellent point. For those who don't know it by heart;
Dragonborn. It's easy to assume that a dragon born is a monster, especially if his or her scales betray a chromatic heritage. Unless the dragon born starts breathing fire and causing destruction, though, people are likely to respond with caution rather than outright fear.
Gnome. Gnomes don't look like a threat and can quickly disarm suspicion with good humor. The common folk are often curious about gnomes, likely never having seen one before, but they are rarely hostile or fearful.
Half-Elf. Although many people have never seen a half-elf, virtually everyone knows they exist. A half-elf stranger's arrival is fol lowed by gossip behind the half-elf's back and stolen glances across the common room, rather than any confrontation or open curiosity.
Half-Orc. It's usually safe to assume that a half-orc is belligerent and quick to anger, so people watch themselves around an unfamiliar half-ore. Shopkeepers might surreptitiously hide valuable or fragile goods when a half-orc comes in, and people slowly clear out of a tavern, assuming a fight will break out soon.
Tiefling. Half-orcs are greeted with a practical caution, but tieflings are the subject of supernatural fear. The evil of their heritage is plainly visible in their features, and as far as most people are concerned, a tiefling could very well be a devil straight from the Nine Hells. People might make warding signs as a tiefling approaches, cross the street to avoid passing near, or bar shop doors before a tiefling can enter.
