THE green-eyed monster. That's the popular and, dare I say it, lamentable description of jealousy. For, some say, the phrase was coined by The Bard himself.

Most people associate green with nature and its calming, even healing effect. As dire predictions of the consequences of global warming gain currency, green is the word on almost everyone's lips. For green is life.

So why is green linked to that maddening, and often destructive, emotion called jealousy?

Some say it's probably because green was associated with bile and sickness, particularly during the time of Shakespeare.

The phrase "green-eyed jealousy" was used by Shakespeare in The Merchant of Venice (written around 1597) while "green-eyed monster" can be found in his Othello (staged in 1604).
That jealousy, especially sexual jealousy, can be downright dangerous has been proven, yet again, by the killing of a lover in a fit of passion.

On July 14, the Shah Alam High Court sentenced R. Rajeswaran, 35, to 12 years' jail for killing his lover, T. Ally Malar, 26, in August 2006.

He pleaded guilty to culpable homicide not amounting to murder.

The quarrel started off as most spousal spats do: over a simple matter. Rajeswaran, returning home to find that the electricity supply had been disconnected, asked why Ally Malar had not paid the bill.

As angry words tumbled over each other, one accusation pounced on another and he let fly his suspicion about her having an affair. And the house came down. He slapped her, she punched him, he got wild and threw a glass table at her.

On Feb 16, 2000, Felda settler Mustafar Yasin was sentenced to 10 years' jail by the Kuantan High Court for killing his wife's lover, Ahmad Ahmin Amri.

Mustafar's warning to his close friend and fellow settler at Bukit Sagu Satu in Panching on Nov 17, 1998 to stay away from his wife exploded into a full-scale verbal war. It ended only when Mustafar, 42, fatally stabbed Ahmad Ahmin, 38, with a dagger.

Jealousy, of course, neither knows bounds nor boundaries. Among the most gruesome cases is the one involving an American soldier.

On April 1, 1994, Stephen Schap, based in Germany, was given a life sentence for cutting off the head of his pregnant wife's lover.

A US military court heard that Schap had attacked his best friend Gregory Glover on Dec 7 the previous year while Glover was telephoning Schap's pregnant wife Diana at a maternity hospital in Fulda, Germany.

After decapitating Glover, Schap took the head to the hospital, showed it to his wife and placed it on a table beside her bed.

But jealousy is not, I hasten to add, solely the province of men. On Nov 27, 2003, divorcee Soh Lay Keow was jailed six years in Singapore for fatally stabbing her live-in lover with a pair of scissors. She had suspected Teo Hwa Eng of visiting Indonesian prostitutes in Batam.

The perpetrators of the crime in the cases above were all victims of jealousy.

Jealousy arises, basically, due to comparison; perhaps even an inferiority complex. A man, for instance, is suddenly forced to compare himself against another, triggering a paroxysm of emotions running the field from fear of being abandoned to loss of self-esteem.

Some say where there is love, there is bound to be a scintilla of jealousy. Some claim that a little bit of jealousy can spice up one's love life. But jealousy has more to do with sex, and possessiveness, than love.

Scientists say jealousy is hard-wired into our psyche. It is, they say, probably due to sexual competition between men eager to pass on their genes, and women's desire to ensure their children are the sole enjoyers of the resources available from their man.

Evolutionary biologists think that success is simply shooting one's genes into the future. Jealousy, they suggest, might just be a warning mechanism that somebody else's genes may be passed on instead.

It's up to us how we act on the warning. Reflecting honestly over the issues involved might help; so might listening without apportioning blame. But if jealousy does become a monster, it is because we have allowed it to.