Cats have 276 different facial expressions, identified by American cat-loving researchers

Recently CNN.co.jp reported the following:

猫の表情は２７６種類、米の猫好き研究者が特定

2023.11.02 Thu posted at 13:37 JST

（ＣＮＮ） 耳を倒したり、目を見開いたり、口の周りをなめたり――。米国の研究チームが猫のそんな顔を調べて２７６種類の表情を特定した。

論文は猫好きな研究者２人が先月、学術誌に発表した。筆者の１人、米ライオンカレッジのブリタニー・フローキウィッツ氏は１日、ＣＮＮの取材に「猫のコミュニケーションはこれまで考えられていたよりずっと複雑だったことが、今回の研究で分かった」と話している。

共同研究者でカンザス医科大学の学生ローレン・スコット氏は、フローキウィッツ氏と共にカリフォルニア大学ロサンゼルス校に在籍していた２０２１年８月から２２年６月にかけ、地元の猫カフェで５３匹の猫を撮影。１９４分の映像から１８６回の猫の交流を記録した。猫は成体の短毛種で、全頭が避妊・去勢されていた。

記録した表情について、猫の顔の筋肉の動きを観察するシステムを使って調べた結果、形態学的に識別できる２７６種類を特定した。呼吸やあくびといった生体作用に関連する筋肉の動きは除外している。

それぞれの表情の意味は特定できなかったものの、４５．７％は和やかな表情、３７％は攻撃的な表情と分類している。

耳やヒゲが前を向いて目を閉じているのは和んでいる表情、目を見開いて耳を頭に付けるように倒し、口の周りをなめるのは攻撃的な表情と分類された。

イエネコは人間の近くにいることからノネコに比べて社会的寛容性が高く、猫同士の交流が増えるために表情が豊かになるとフローキウィッツ氏は解説する。

今後は猫の表情の意味について、さらに研究を深めたいとしている。

Translation

(CNN) The ears folded down, eyes widened, and licking around the mouth. A research team from the United States studied the faces of cats and identified 276 different facial expressions.

The paper was published in an academic journal last month by two cat-loving researchers. One of the authors, Brittany Frokiewicz from Lyon College in the US told CNN on the 1^st that ``This study shows that cat communication is much more complex than previously thought.''

Co-researcher Lauren Scott, a student at the University of Kansas Medical School, photographing 53 cats at a local cat cafe between August 2021 and June 2022, while she and Frokiewicz were both students at the University of California, Los Angeles. They recorded 186 cat interactions from 194 minutes of footage. All cats were adult short-haired cats and had been spayed or neutered.

As a result of examining the recorded facial expressions using a system that observed the movements of cat facial muscles, they identified 276 types that could be morphologically distinguished. Muscle movements related to biological actions such as breathing and yawning were excluded.

Although the meaning of each expression could not be determined, 45.7% were classified as peaceful expressions and 37% as aggressive expressions.

With its ears and whiskers pointing forward and its eyes closed was classified as a calm expression, while with its eyes opened, ears folded down to the head, and licking around the mouth was classified as an aggressive expression.

Frokewicz explained that domestic cats had higher social tolerance than feral cats because they lived close to humans, and their facial expressions became richer because of the increased interaction between cats.

In the future, he would like to further research into the meaning of cats' facial expressions.

              So, a research has studied the faces of cats and identified 276 different facial expressions. One researcher explains that domestic cats have higher social tolerance than feral cats because they live close to humans, and their facial expressions become richer because of the increased interaction between cats. I am wondering to want extent do cats understand each other’s facial expressing.