How to spot whodunnit: academics crack Agatha Christie’s code.

NEWS! On the 125^th Anniversary of Agatha Christie’s birth, scientists reveal the key clues behind the world’s best-selling novelist

• Panel of experts reveal the secret to Agatha Christie – the world’s best-selling novelist’s success
• Greatest mystery in fiction solved – how to spot ‘whodunnit’
• Where the novel is set, the primary means of transport used throughout the book and how the victim dies, are all key factors that give away who the killer is
• New research released today was commissioned by TV channel Drama to celebrate their Agatha Christie Hour, weekdays at 8pm, 3^rd – 14^th August

As Agatha Christie fans across the world celebrate the 125th anniversary of the best-selling author’s birth, new research reveals the formula for her incredible success and crucially – how to spot whodunnit!

The research, commissioned by UKTV channel Drama for their Agatha Christie Hour at 8pm, weekdays from 3^rd – 14^th August, tasked a panel of experts including Dr. James Bernthal from the University of Exeter; Dr. Dominique Jeannerod, Senior Research Fellow at the Institute for Collaborative Research in the Humanities at Queens University; and data analyst Brett Jacob, with analysing a selection of Christie’s top selling mystery novels** to discover the secret to her success and the ultimate formula for predicting who the killer is.

Key Findings:

• The killer will be introduced within the first half of the book
• The killer is likely to be emotionally involved with the victim, most killers are spouses or blood relatives of their victim
• If there are a lot of land vehicles in the story, the killer is most likely female
• If there are a lot of nautical vehicles and aircraft in the story, the killer is most likely male
• If the victim is strangled, the killer is most likely male (or male with a female accomplice)
• If the setting is a country house, the killer is most likely female (75% chance)
• The language used throughout the book to describe a female killer is usually more negative than when describing a male killer
• Female killers are normally discovered due to a domestic item
• Male killers are normally found out through information or logic
• If Poirot is the detective, and the cause of death is stabbing, the killer will be mentioned more frequently at the beginning of the book
• If Miss Marple is the detective, and the motive for the murder is money/affair, the killer will be mentioned more in the later stages of the novel than the beginning.

Adrian Wills, General Manager for Drama said “Agatha Christie is the best-selling novelist of all time, so the television adaptations of her books are hugely popular.  To mark the 125^th anniversary of her birth, the Drama channel decided to pull together 10 nights of some of her most famous stories in the Agatha Christie Hour, weeknights at 8pm from August 3^rd. Given her on-going popularity, we wanted to know her formula for success, especially since the whodunit is such a classic of the crime drama genre.  We hope that her legions of dedicated fans will revisit their favourite whodunits with a better understanding of how to crack the ultimate code.”

Christie’s Work:

The study found that Christie features similarities in language style, word length and sentence length across her works. According to a team of researchers lead by Dr Jeannerod, a key element of Christie’s writing style is to keep it simple; using middle-range language and repeating it. In fact, according to research, the most used word in Christie’s novels is ‘said’.

Jeannerod’s team also found that the structure of a Christie novel can be simplified down to a list of key events: the body will be found early on; a closed group of suspects (achieved either by remote location or the confines of a social group) will be presented to the reader; the detective will then be introduced and a series of red herrings will follow; and finally, after the outcome, the solution will wrap up the story quickly and efficiently, leaving the reader satisfied.

The Main Clue:

As any mystery novel goes, the reader is subjected to the occasional red herring. Clues need to offer the reader an experience that satisfies expectations whilst avoiding disappointing predictability. According to Dr. Bernthal, Christie’s novels tend to include a “main clue” which is revealed “approximately half way through the text” and “it will usually be highlighted as it appears in the text,” so the reader is likely to remember it.

However, according to Bernthal, even if the main clue is easily missed or consciously skimmed over by the author, with Christie’s work, because the “the reader already remembers the clue, this creates an impression of fair play,” so the reader doesn’t feel cheated by the addition of a random detail they could never have spotted. He also reveals that Christie’s female killers tend to be given away by domestic items whilst the male killers are discovered by information or logic.

Working out the Formula:

Relationship to the victim (=)

Dr. Bernthal’s research highlighted that the killer is likely to be emotionally involved with the victim; the most common relationship being a spouse or relative. Furthermore, if the killer’s victim is their spouse, the most probable motive will be love, whereas murders committed by blood relations are more varied in motive.

Primary means of transport associated with the novel (=)

According to Dr Jeannerod’s team, the novels which include a female killer are more likely to feature land vehicles (such as cars, vans, trucks), whereas novels with a male killer are more likely to involve nautical vehicles and aircraft (such as boats and planes).

The sentiment of the language used in association with the killer (=)

By using a sentiment analysis program called “Semantria”, Dr Jeannerod’s team found that in general, Christie uses more negative language to describe her female killers, whereas with male killers, she uses “higher levels of neutral or positive sentiment”. It was also found that in her later novels, Christie portrays her culprits in an overall more negative light.

Method of murder and the detective characterized in the novel (=)

Jeannerod’s team also found that if the victim is strangled, the killer is more likely to be male (or male with a female accomplice) and that there is a correlation between the killer being a doctor and the victim dying from either stabbing or strangulation. The results also suggest that if Poirot is the featured detective, and the cause of death is stabbing, it is extremely probable that the killer will be mentioned more frequently at the beginning of the book rather than in the concluding chapters. However, if the detective is Miss Marple, and the motive for the murder is money/affair, “the culprit will be mentioned more in the later stages of the novel than the beginning.”

Setting for the novel (=)

Dr. Bernthal’s research revealed that if the setting is a country house, there is a 75% chance that the killer will be female.

Chapter of introduction of the killer (=)

Bernthal also discovered that the murderer will be introduced within the first half of the novel, and almost always within the first 20% of the book.

Number of mentions of the killer ()

Furthermore, the later the book was published, the more the murderer will be mentioned throughout the novel according to Dr Jeannerod’s team. In fact, it was found that on average the culprit had 11.7 new mentions with every new novel. The findings also reveal that “there is a 27% chance that the culprit will be mentioned most in the first quarter of the novel, a 36.5% chance for the second quarter, an 18.5% chance in the third quarter, and an 18% chance for the fourth quarter.”

Agatha Christie Hour will air on TV channel Drama at 8pm, weekdays from 3^rd – 14^th August