According to some Christian outlooks we were made for another world. Perhaps, rather, we were made for this world to recreate, reclaim, redeem, and renew unto God's future aspiration by the power of His Spirit. - R.E. Slater
Secularization theory has been massively falsified. We don't live in an age of secularity. We live in an age of explosive, pervasive religiosity... an age of religious pluralism. - Peter L. Berger
Exploring the edge of life and faith in a post-everything world. - Todd Littleton
I don't need another reason to believe, your love is all around for me to see. – anon
Thou art our need; and in giving us more of thyself thou givest us all. - Khalil Gibran, Prayer XXIII
Be careful what you pretend to be. You become what you pretend to be. - Kurt Vonnegut
Religious beliefs, far from being primary, are often shaped and adjusted by our social goals. - Jim Forest
People, even more than things, need to be restored, renewed, revived, reclaimed, and redeemed; never throw out anyone. – anon
Certainly God's love has made fools of us all. - R.E. Slater
An apocalyptic Christian faith doesn't wait for Jesus to come, but for Jesus to become in our midst. - R.E. Slater
Christian belief in God begins with the cross and resurrection of Jesus, not with rational apologetics. - Eberhard Jüngel, Jürgen Moltmann
Our knowledge of God is through the 'I-Thou' encounter, not in finding God at the end of a syllogism or argument. There is a grave danger in any Christian treatment of God as an object. The God of Jesus Christ and Scripture is irreducibly subject and never made as an object, a force, a power, or a principle that can be manipulated. - Emil Brunner
Ehyeh Asher Ehyeh means "I will be that who I have yet to become." - God (Ex 3.14)
Our job is to love others without stopping to inquire whether or not they are worthy. - Thomas Merton
The church is God's world-changing social experiment of bringing unlikes and differents to the Eucharist/Communion table to share life with one another as a new kind of family. When this happens we show to the world what love, justice, peace, reconciliation, and life together is designed by God to be. The church is God's show-and-tell for the world to see how God wants us to live as a blended, global, polypluralistic family united with one will, by one Lord, and baptized by one Spirit. – anon
The cross that is planted at the heart of the history of the world cannot be uprooted. - Jacques Ellul
The Unity in whose loving presence the universe unfolds is inside each person as a call to welcome the stranger, protect animals and the earth, respect the dignity of each person, think new thoughts, and help bring about ecological civilizations. - John Cobb & Farhan A. Shah
If you board the wrong train it is of no use running along the corridors of the train in the other direction. - Dietrich Bonhoeffer
God's justice is restorative rather than punitive; His discipline is merciful rather than punishing; His power is made perfect in weakness; and His grace is sufficient for all. – anon
Our little [biblical] systems have their day; they have their day and cease to be. They are but broken lights of Thee, and Thou, O God art more than they. - Alfred Lord Tennyson

Thursday, May 23, 2013

Oh the Games We Play with God and Church: A Study of Game Theory and Favorable Outcomes

 
kids and sunset

The games we play
http://gospelfutures.org/2013/04/04/the-games-we-play/

by Neil Williams
April 4, 2013

When the mathematical genius John von Neumann (1903 – 1957) sat down to figure out how he could use mathematics to improve his poker playing, little did he realize the repercussions of his inquiry, not only in mathematics but also in almost every other field of inquiry. Considered the father of game theory, Neumann, with the economist Oskar Morgenstern, produced the founding textbook Theory of games and economic behavior that revolutionized economics.
 
When playing a game such as poker, you have limited information (you cannot see all the cards), other players will deceive you, and they intend to win. Game theory is about what decisions and strategies you should take to achieve a favorable outcome.
 
Games consist of three main areas: players, strategies, and outcomes. A basic form of a game is a two-person game where a win for one player means a loss for the other. Known as a zero-sum game, the outcome of this type of game adds up to zero—a win (+1) is offset by the other player’s loss (-1). These games are one hundred percent competitive with no co-operation between players.
 
In a positive-sum game, your win does not mean a total loss for your opponent and involves some co-operation as well as competition. In such games, all players benefit, the outcome being positive. The cliché “win-win situation” refers to a positive sum game where all players benefit from the outcome. Trade between two nations is a classic example of a positive-sum game.
 
Game theory started in mathematics, but expanded to other disciplines including psychology, economics, politics, evolutionary biology, warfare, and theology. We can conceive of most, if not all, interactions in terms of a game: people bidding on an ebay auction, the Cuban missile crisis, a couple arguing with each other, a job applicant negotiating a salary, airlines overbooking flights on the assumption that some passengers will not turn up, a criminal taking a plea agreement instead of a jury trial, a person sacrificing their life for the sake of another.
 
The ways games are structured have implications for relationships and transformation. A married couple may frame an argument as a zero-sum game where each maneuvers, like game pieces on a board, to achieve a winning position—a position that means a defeat for their partner. Seminaries, religions, churches, and para-churches may frame their institutional identity as zero-sum games. Rules and beliefs establish and dictate how and why the game is played and who may play it. If you play, you play to win. If you play, you may only play as long as you stick to the parochial system; otherwise you are out. Blogs—from religious to atheist—will make little progress in relational transformation if a zero-sum mentality demands winners and losers.
 
In these zero-sum games, a community builds a petty game with rules and beliefs that exclude a multitude of other realities, creating a system of thought that is placed above people and transforming relationships.
 
The most famous example in game theory is the Prisoner’s Dilemma devised by Merrill Flood and Melvin Dresher. The basic idea of the Prisoner’s Dilemma is this: The police have arrested you and your partner-in-crime on suspicion of robbing a bank. Lucky for you, the prosecutor lacks sufficient evidence to convict. You and your friend, however, are locked in separate, isolated cells and the prosecutor comes to you with a few options:
 
• Confess and we will let you go free and put your friend behind bars for 15 years.
• Don’t confess and if your partner confesses we will put you in jail for 15 years.
• If you both confess, we will drop the penalty to 3 years.
• If neither of you talk, well, we have enough to convict you on a lesser charge and put you both away for 6 months.

What do you do? The dilemma is this: the rational choice is to confess, no matter what your friend does. If they do not confess, you go free. If they confess, you only get three years instead of fifteen. But here is the catch: if you both keep silent the jail time is even less—only six months instead of three years. Do you confess or stay silent, or in the language of game theory, do you defect or cooperate? In the Prisoner’s Dilemma, the rational choice is to defect, but the best possible outcome for both of you is to cooperate and keep silent.

Cooperation needs a relational connection. To achieve the best possible outcome we need trust, but trust is vulnerable to exploitation. Do you trust your friend enough, because if you co-operate and they deflect, then you are behind bars for fifteen years? In this case, game theory underscores that trust and cooperation achieves the best outcome for everyone. The rational choice is not always the best. The relational choice is the best.

Game theorists have studied many variations of the Prisoner’s Dilemma including iterative cases. Most interactions in life are not once off. Instead of a one-off game, what happens when we have the opportunity to repeat the game a hundred times? What strategy should we now adopt? The answer was discovered in two experiments organized by the political scientist Robert Axelrod, author of the highly influential The Evolution of Cooperation, a book that opened with the question: “Under what conditions will cooperation emerge in a world of egoists without central authority?” Axelrod invited game theorists in economics, psychology, sociology, evolutionary biology, political science, mathematics, physics, and computer science to submit computer programs that would compete against each other in an iterative Prisoner’s Dilemma scenario. What program would receive the highest score? One that was more willing to cooperate? One that defected all the time?

Axelrod describes some of the programs:

Massive retaliatory strike: cooperate at first, but after a defection, retaliate for the rest of the game.

Tester: this program tries to find out what you are like, so it attacks in the first move. If met with retaliation, it will cooperate for a while. Then it will defect again, just to see how much it can get away with.

Jesus: always cooperate

Lucifer: always defect

If Tester plays Massive retaliatory strike, they both do poorly. Tester defects on the first move and Massive retaliatory strike defects from them on.

If Lucifer plays Jesus, Lucifer wins.

Axelrod thought that the winning program would contain thousands or tens of thousands of lines of code. The mathematical psychologist Anatol Rapoport submitted the highest scoring program, and it was also one of the simplest, five lines of code, a tit-for-tat program, where co-operation was met with co-operation, and defection met with defection. Overall, the top ranking programs were all nice, and on average, the defector programs scored significantly lower.

Axelrod described the tit-for-tat program as nice, retaliatory, forgiving, and clear. It is nice so it starts with co-operation. It retaliates to discourage the other player from continued defection. It forgives and quickly restores cooperation. It is clear in that it is not duplicitous; its actions are straight forward and easily interpreted, thus providing a basis for long-term cooperation. The one distinguishing feature of programs that did well versus those that did poorly, was being nice. In other words, start with trust and co-operation, and avoid unnecessary conflict. A nice player is never the first to defect and co-operates whenever the other player co-operates. Surprising, nice people finish first.

Tit-for-tat is the most successful strategy when the Prisoner’s Dilemma is played numerous times. You start with co-operation and basic trust. If the other player cooperates, you continue to cooperate. If they defect, then you respond with defection. The strategy punishes those who take advantage of other players’ trust and generosity. The strategy, however, also allows for a change of mind. After deflecting, your opponent may once again decide to co-operate with you. In tit-for-tat, you respond with cooperation.

To express these ideas in theological language, for an iterative game that achieves the best outcomes for all players, we need trust, forgiveness, and repentance. Trust is necessary for cooperation and as we cooperate we repeatedly send the message that we are trustworthy. In a repeated game, however, there will be failures by all players. Forgiveness is necessary, for it allows us to continue to play the game when a defector decides to cooperate. Repentance is necessary, for it allows us to change from defecting to cooperating. It turns out that forgiveness and repentance are even more important than first realized by game theorists. In the complicated world of relationships, signals can be misinterpreted. Perhaps a player intended to cooperate but her actions are misconstrued as a defection. A player can make a mistake or perhaps they just need a second chance. Does the game now have to continue with repeated retaliation? Here is where a small tweak optimizes the tit-for-tat program; named “generous tit-for-tat,” it will randomly throw in a forgiveness about ten percent of the time. Call it grace—an undeserved mercy that breaks a cycle of repeated defection.

Playing games that benefit all players depends on healthy relationships. If we are in relationship with other players, we are more likely to cooperate than defect. Relationships encourage a willingness to forgive and repent. Relationships temper our fear that we will be tricked. And relationships temper our greed that seeks outcomes advantageous to us while at the expense of other players.

The tit-for-tat strategy illustrates that a relational approach is far from being a sugary pushover. Unconditional pacifism is a losing strategy because psychopaths and con-artists are always scouting to exploit some unwary soul, softie, or sucker. A relational approach that includes trust, forgiveness, and repentance, also includes a credible threat of repercussion for defection. “If another person sins, rebuke that person; if there is repentance, forgive” (Luke 17:3). A relational approach will retaliate, for example, against the zero-sum games of patriarchy, racism, and other forms of bigotry. It starts with trust and co-operation, is quick to forgive, but will also punish defectors.

There is, however, a problem with a game repeated a finite amount of times. If you know the game is finite and is going to end after a hundred moves, then even after repeated cooperation, the rational strategy is to defect in the final move. Take the money and run—there is no retaliation because the game has ended. This suggests the importance of infinite games, games that continue indefinitely, where there is no end and therefore no temptation to defect at the end.

The religious scholar James Carse has developed this idea in Finite and infinite games: a vision of life as play and possibility. Carse distinguishes between two types of games: finite and infinite. There are substantial differences between the characteristics and goals of finite and infinite games. Carse writes, “A finite game is played for the purpose of winning, an infinite game for the purpose of continuing the play.” A finite game ends when somebody wins, thus finite games need fixed boundaries and unchanging rules to decide who wins. Because of the boundaries of finite games, it is impossible to play an infinite game within a finite game. In contrast, infinite games are ongoing and have no fixed boundaries or rules. Thus for Carse, “Every move of an infinite player makes is toward the horizon. Every move made by a finite player is within a boundary. Every moment of an infinite game therefore presents a new vision, a new range of possibilities.”

For Carse, the goal of players of finite games are to become powerful, entitled, Master Players, supremely competent in every detail of the game that they essentially play as if the game is already completed. And because a finite game always ends, finite players have to repeatedly play to prove they are winners. In a finite game, the last thing you want is surprise, whereas in an infinite game, surprise is a reason for continuing to play. An infinite game is fluid and open ended, and the reasons for playing an infinite game are not to become powerful or to win. The concern of infinite players is “not with power but with vision.”

Finite games are defined by their boundaries, whereas infinite games are defined by their horizon. Boundaries are fixed and clear, and one cannot move beyond a boundary. But in an infinite game the horizon is open-ended—it is a direction toward we move, a place we never reach, a journey always open to newness and surprise.

Is Christianity a finite or an infinite game? What should it be? We would be naïve to assume that there is one message of Christianity. In the church’s two thousand year history, people have expressed a multitude of different ideas about Jesus and different versions of Christianity.

It is possible to conceive of Christianity as a finite or an infinite game.

1. Christianity formulated as a finite zero-sum game: we win; everyone else loses. We are master players, essential to this grand game, a game that has a definitive conclusion resulting in a win for us, and a loss for everyone else. The game is one of good versus evil, us versus them. Our particular beliefs and rules establish fixed boundaries of the game, and distinguish us from other Christians and their games. You may join our game and play, but only if you accept the rules that structure and direct our game. The benefits include power, titles, solid explanations, fixed boundaries, solidarity with us, and a winning hand.

As a finite game, Christianity has had little difficulty aligning itself with patriarchy, slavery, racism, hate crimes, torture and death of infidels, and colluding with empires—Roman, Spanish, English, American. In each case, there are clear winners and losers.

If Christianity is setup as a megalomaniacal finite game, it is impossible to play an infinite game. By its nature, it excludes the possibility of the gospel story as an infinite game.

2. A vision of Christianity as infinite play: Jesus creates a new playground that plays fast and loose with the rules, dissolves boundaries and fixed beliefs, and opens new horizons of possibility. In an infinite game, the central themes of the gospel story—incarnation, life, death, resurrection—are articulated in ways that place people and relationships above the system. In Christ, there are no winners or losers—there is neither Jew nor Gentile, slave nor free, male nor female (Gal 3:28). Jesus is not a master player but an infinite player who invites all to an infinite game by including the excluded and rebuking the excluders. Anyone can play, no titles are awarded, no winners are announced, and boundaries are replaced by a gospel horizon.

This infinite game is characterized by vision and openness, where beliefs and rules are continually rewritten in order to keep the game going. To put boundaries on an infinite game, destroys it and stops the game. There is no end of play, and if need be, infinite players will choose death over life in order for the game to continue.

The gospel story as an infinite game contrasts with the beliefs and rules of finite games. Beliefs are certain and bounded. Stories have development, surprises, twists, paradoxes, uncertainties, even contradictions. Beliefs often end the conversation. An infinite story invites further discovery, directs us to the horizon, continues the game, and reformulates the conversation.

If the story is a great pyramid of inspiration and awe, beliefs are limestone rocks dug out from the structure. Beliefs are not necessarily bad, we just need to recognize them for what they are—abstractions from the story, attempts to collate our understanding, pieces of rock dismantled from the magnificent structure. Sometimes these rocks are useful for constructing smaller buildings, but often people just throw them at others. Beliefs are ready tools to create finite or zero-sum games that leverage power over others, but if all we have is rocks, we have reduced the grand story to rubble and can no longer resonate with its openness, poetry, surprises, and vision.

There is an infinite game, an infinite story, which starts: in the beginning was the game maker, and the one who plays, and the one who invites others to join the game and continue the play....


 

Cometh the End-of-Days ... Too Soon Lived, Too Shortly Over ...


Tonquin Valley, Jasper National Park, Alberta


Sometimes a picture, or a song, seems to fit us. Today's picture and song seems to fit me by their emotional moodiness and abject honesty before God as to our fit-and-frame, our wonder-and-encouragement, against each day's sometimes too heavy challenges. It is not often we find ourselves so alone with God as at the times in our lives when momentous change comes.... The kind of change you have been prepared for all your life and must now cross over to its withdrawn boundaries. Boundaries of mortality and death; of health and good keep; of bright pasts fading into the dimming lights of lengthening futures marking finality's end; of beginning and start.
 
These past many weeks I have been making peace with my dad's steady decline held within Parkinson's unfeeling grip. It began late one Thursday afternoon when called home by an aged mother unable to stand him up and move him to the bathroom. Arriving I saw immediately the heavy grip of pneumonia raging through his body, his fever, shakiness, and delirium having lain too long unrecognized. Unable to do no other, I picked dad's painful body up and carried him through the house's too-narrow hallways and doorways. First undressing, than cleaning, and finally re-dressing him in preparation to leave the home he loved and wished to stay. Then giving him some few minutes to say goodbye as we packed to all that he once knew - to his past and to his even more distant memories - before driving both dad and mom to the hospital many long miles away. This same trip had been made many years ago when dad had had two separate heart attacks on the same night. But this illness was different. It held a finality to it that I couldn't shake nor wished its interminable end.

Even so, that night proved to be the watershed in a life that clung bravely to health even as his body wore away through loss of muscle control, weakness, and failing health. Dad's self-imposed dignity was lost years ago as he fell down hard repeatedly when become unbalanced in motion, standing, or stooping. Through hot tears he stubbornly clung to life as he remembered it - even through the dark dismay of knowing that with each fall the disease within his body increased its unholy presence. First came my brother's purchase of a Kawasaki Mule for dad to run around the property as he lost the ability to operate safely his tractor, car, and truck. The lawn mower was the next to go because of the pain that jarred his pain-whacked body over the bumps of the uneven ground. Then came the lift chairs, canes, and walkers; the wheelchairs, medicines, diets, and strengthening therapies. And with each event came more loss and a greater personal conviction to endure bravely under God's presence and love what 'ere may come. As it surely would.
 
So that even now, as my dad continues his steady decline within Parkinson's unfeeling grip, he bravely lives each passing day in the hope of God's sustaining mercy for a finality no one ever seeks until, at the last, it can no longer be refused. To this has come my family's deep sense of loss and inability to do anything but face with dad his own resolve knowing life has passed and that eternal life will shortly begin. It is a common ending all know and are faced with - some with a greater degree of loss and fate than others less blessed by challenge, suffering, and struggle. For myself, it is working with an institutionalized medical system to help make dad comfortable until the end. Nor to give up too soon despite his languishing spirit. And yet, even this does little to comfort me as I watch dad's unending pain-and-loss mount against a pneumonia that comes-and-goes, filling his lungs with unwanted fluids unable to swallow properly, while watching other parts of his body cease in their functioning, and knowing that at some point even I must let go my stubborn hope of dad's comfortable survival.
 
At some point we each must rethink our life, its accomplishments and failures, its disappointments and steady challenges, knowing that all we are, and have done, is in our Lord's faithful hands to do with as He will. Mine is to let go of a father who always had my best interests at heart. And to visit an area hospice agency this week seeking answers to medical ethics questions I felt too guilty to admit... realizing that dad's time is drawing to a close. Asking the question, at what point does one reframe the present so that a love one's life can be accepted as worn out, and coming to its end. That it is no longer able to be lived out to the satisfaction of its owner. To tenderly speak to a father's heart and not his head. To speak words of assurance, of comfort and love, of truth and loss. of life and death. Words which might not be heard in the weeks or months that lie ahead. To prepare a soul even as he had prepared mine own many years earlier for life's hardships and joys.
 
Worse for me, is to watch my family work through their various emotions of grief and loss, meaning and well-being, as I contemplate how to negotiate and coordinate dad's care from sub-acute nursing services to in-home care and palliative services. Or when to bring in hospice once all curative hope has ended so that we might prepare for the tough times ahead without feeling as though we were giving up. Part of the solution has been in allowing dad's growing medical instability to be shared and known to the family from the doctors and nursing staff. By sharing the finality of his medical tests. And by admitting the sheer volume of tell-tale signs lying everywhere present except within the hearts of those who would deny their harsh realities. By sharing medical findings, temporary solutions, paperwork, and financial considerations. And in allowing quiet, timely conversations, to unfold with a sister or brother, a mother and relatives, one's own son and daughter, nieces and nephews, as they can be bourne within weary hearts and minds coming to similar conclusions in their own separate ways.

For it is to the Lord's mercies we are driven at such times. To whom we pray mercy for a father once too busy for family because of work and bills when raising a young family. For a dad whom my brother and I would wade out through the morning clovered dews to watch plow up fallow ground bowed over a chilly, steel tractor's frame. Whom we'd listen to on harsh blizzard mornings held within the rusted, unyielding whines of a decaying tractor pushing its plow through high snowy drifts into heaps while we played and tumbled underneath it all. Who raced across the fields to a fire siren's call or answered the pleas for help as a duty-bound police officer. Who taught us to handle a gun safely even as he was instructed by his father and uncles. And to hunt sure-footedly in the tangle of undergrowth and viney fencelines that we trampled across even as he learned it soldering along the Korean DMZ. All the while telling us to follow alertly the trace of our German Shorthair with his nose to the ground before setting into point. To enjoy the art of travel and adventure as we explored all parts of North America from its southern Texan borders to furthers Canadian reaches each summer for the four to five weeks that we would spend on the road camping along the nation's infant highways and lonesome, wild byways. To listen to his patient coaching and instruction on the ball fields. And to love the time we spent in playing catch with dad in the backyard. Or out in the nearby mown fields of the family's farm as we hit his lofting pitches. To be at his side at large family reunions meeting distant relatives he knew well. Or at marital celebrations. Or in church. Or the too many family burials we seemed to endlessly attend. And sadly, to bury a torn brother ripped apart by the angry delusions of bi-polarism - whose untimely death tolled upon the heart of his beloved father consumed in grief.

Life has its cycles of despairs and happiness. And it is to each of these that we must pass as best we can, relying on God's wisdom and judgment against our own frailties, emotional upheavals, failures, and wandering hearts. It is at such times that I wish to feel intensely the losses and gains, the miseries and successes, even the very heart of God during life's untimely storms and griefs. To not abandon these very difficult times but to listen, watch, and live through them as they were meant to be under sin's penalty and life's enduring hardships. To find within death the beating heart of life's redemption knowing that nothing is lost to a God who sovereignly reigns and wishes to recreate. Who loves with a burning heart of passion even as we would. Who by His Spirit tells us of His risen Son's victory against death's greedy hand. Who raises the dead to life even within the very sallow lives we live thinking ourselves beyond God's mercies and kindnesses, His grace and compassion. Ignoring all but the vanity around us thinking these only compose a life made for the grave when they were really made for eternity's unfurling eons of renewal and reclamation. Nay to life's cycles of despairs and happiness we each must look into the heart of God to see its truer end and everlasting promise.

For it is in this Almighty God that we rest and find our peace to the hard questions we cannot discover. Nor to the deep answers that would elude us as we helplessly watch the hot, living agonies experienced by a loved one suffering so tragically within the strengthening grip of consuming disease. At the last - even as in its beginning - our hope ever rests in Jesus' resurrection and all that His atonement means to living life fully and completely. Jesus is our Rock. He is the sure ground upon which we tread. Whom we must abandon ourselves unto, and to nothing less. Both now as always. For it is to God's wisdom and faithfulness that we rely - and not upon our own feeble devices. We live in God's creation as His own rebirthed creation. It is how He has made us. Even as we would hold onto a temporality meant only to slip into eternality's permanence by His guiding, all-suffering heart of compassion and mercy. For such a one who knows these things, and believes with his heart, will come the blessing of God's steady assurance and all-consuming Spirit. A Spirit far larger than any disease we may bear - even that of sin's curse. So then we are to be at peace, and know that our end-of-days are held within Him who is, and has become to us, even our own End-of-Days. Forever and always. Life without end.
 
R.E. Slater
May 23, 2013
 
 
ESV
 
14 For this reason I kneel before the Father, 15 from whom every family[a] in heaven and on earth derives its name. 16 I pray that out of his glorious riches he may strengthen you with power through his Spirit in your inner being, 17 so that Christ may dwell in your hearts through faith. And I pray that you, being rooted and established in love, 18 may have power, together with all the Lord’s holy people, to grasp how wide and long and high and deep is the love of Christ, 19 and to know this love that surpasses knowledge—that you may be filled to the measure of all the fullness of God.
 
20 Now to him who is able to do immeasurably more than all we ask or imagine, according to his power that is at work within us, 21 to him be glory in the church and in Christ Jesus throughout all generations, for ever and ever! Amen.
 
 
 
 
 
 
 Published on May 10, 2013
Music video by Lana Del Rey performing "Young and Beautiful"
from the Great Gatsby soundtrack: http://smarturl.it/GatsbyMusic

Produced by Daniel Heath
Video Director: Chris Sweeney
Shot By Sophie Muller
Video Producer: Adam Smith, Jacob Swan-Hyam

(C) 2013 Lana Del Rey, under exclusive license to Polydor Ltd.
(UK). Under exclusive license to Interscope Records in the USA





My Father's Final Passage and Continuing Voyage