When Shoukoufeh, an English literature student from a backwater town, set out to rent an apartment for her here in the capital, she first stopped at a jewellery store and picked up a $5 wedding ring.
Accustomed to living with lies to navigate the etiquette of Iranian society, where women are traditionally expected to live with their parents or a husband, the 24-year-old would prominently flash her fake white-gold band to real estate agents and landlords who would otherwise be reluctant to lease an apartment to a single woman.
"To them and my neighbours, my roommate and I are two married women away from their husbands to pursue our studies," she explained. "In reality, we are of course both single."
There are no official statistics on the number of women living by themselves in big cities in Iran. But university professors, real estate agents, families and many young women all say that a phenomenon extremely rare just 10 years ago is becoming commonplace, propelled by a continuous wave of female students entering universities and a staggering rise in divorces.
The shift has left clerics and politicians struggling to deal with a generation of young women carving out independent lives in a tradition-bound society, away from the guidance of fathers and husbands. Desperate to stop the trend, the government introduced a campaign to promote quick and cheap marriages - but it backfired, experts said, by cheapening an institution deeply anchored in Iran's ancient culture.
That has left the young women to develop strategies to fend for themselves in a society where social codes are often based on deep suspicion of female sexuality. Shoukoufeh, who would not give her full name for fear of losing her lease, said that prying eyes often peek through the cracks of doors whenever she walks down the hallway. But she said she draws strength from her parents, who support her choice to live alone.
"They know I want to be independent," she said decisively. "They understand times have changed."
In the not-so-distant past, single women had to endure severe social stigmatization, suspected of having loose morals or dismissed as spinsters who were failing to fulfill their role in life.
But that is changing in the big cities, in large part because of their sheer numbers, but also because of the prevalence of satellite television, social media and cheap foreign travel, many Iranians say, which have helped to change attitudes.
University enrolments have been rising strongly in Iran over the last decade, and women now account for nearly 60 per cent of the total. Having raised their horizons in four years of college, many of these women have trouble finding husbands they consider their equals.
In the same period, divorces have increased by 135 per cent, forcing society, if not its leaders, to begin to accept single women. "Many of my friends, especially those who came from small towns to study in Tehran, are living by themselves," Shoukoufeh said. "For many girls of my age group, living single is the norm now."
Big city life, with its opportunities and freedoms, has created new ambitions, she said, and allowed her and her friends to lead lives completely different from their parents'.
"When my mother was young, finding a husband and having children was the only measurement of success," said Shoukoufeh, who is planning to leave Iran to pursue her studies. "Now - at least to me - it is the least important factor."
Politicians and clerics are warning that an entire generation is growing up with values that are anathema to the traditional ones upheld by the state.
For those in power, who promote motherhood as a holy virtue, but also see higher education as a nationwide ambition, marriage is the only solution for the growing number of single women.
"Young people who are not married are nude, as marriage is like divine clothes to cover them," a leading ayatollah, Kazem Saddighi, said last week in a sermon. He also urged all Iranians to have children and follow the example of the household of the Prophet Muhammad.
In Iran's Shiite theocracy, Fatima Zahra, the daughter of the prophet and a widely admired saint, is a role model of womanhood. According to Islamic tenets, she was a mother and guardian of her family, but also politically active and ready to sacrifice herself for her husband, Ali, the founder of Shiism.
How Mrs Fatima's actions are interpreted in modern times is up to the clerics. Yet, while there are many different religious interpretations of what she represents, it is clear that single womanhood is not among them.
Iranian society is still far from many Western countries, where marriage and motherhood are increasingly seen as optional. But to prevent a shift in that direction, Iran's Supreme Council of Cultural Revolution, which sets out social policies, ordered in 2006 that marriage be made as cheap and easy as possible. A key objective set out then was to "reduce expectations and formalities" so that families are "encouraged to help their children to marry."
Traditional wedding ceremonies are elaborate and expensive in Iran, often with a hefty dowry thrown in, all of which makes it hard for many singles - men or women - to marry even if they want to.
Promoting a quick-fix solution of its own, President Mahmoud Ahmadinejad's government organized mass weddings for students and for a while gave out cheap loans to young couples.
But state involvement in marriages seems so far to have been counterproductive, experts say.
"Instead of making marriage more attractive, they turned it into fast food," said Mohammad Amin Ghaneirad, the head of the Iranian Sociological Association. "Because of this attitude, marriages are dissolved as easily as they are solemnized."
In the past, divorced women were condemned to lives of solitude, hidden away in their childhood bedrooms at their parents' houses, where society expected them to remain for the rest of their lives.
But the enormous increase in broken marriages, combined with the higher wages that come with a university degree, is allowing many women to redefine success. Increasingly their parents agree.
"To my surprise, my parents also wanted me to live by myself," said Nazanin, aged 35. Her above-average income as a manager of a cosmetics company allowed her to rent an apartment after she left her husband because of his drug addiction.
"I strongly believe in God," she said. "He wanted this for me. My single life is so much better."
At her work everybody is divorced, said Nazanin, who did not want her family name mentioned for reasons of privacy. She recently moved into a new apartment building where everybody is over 30 and single.
"Society has no option but to accept us," she said. "I hope the state will follow."
© 2012, The New York Times News Service